• README

  • This is a multi-threaded multi-pool GPU, FPGA and ASIC miner with ATI GPU
    monitoring, (over)clocking and fanspeed support for bitcoin and derivative
    coins. Do not use on multiple block chains at the same time!
    
    This code is provided entirely free of charge by the programmer in his spare
    time so donations would be greatly appreciated. Please consider donating to the
    address below.
    
    Con Kolivas <kernel@kolivas.org>
    15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ
    
    DOWNLOADS:
    
    http://ck.kolivas.org/apps/cgminer
    
    GIT TREE:
    
    https://github.com/ckolivas/cgminer
    
    Support thread:
    
    http://bitcointalk.org/index.php?topic=28402.0
    
    IRC Channel:
    
    irc://irc.freenode.net/cgminer
    
    License: GPLv3.  See COPYING for details.
    
    ---
    
    EXECUTIVE SUMMARY ON USAGE:
    
    After saving configuration from the menu, you do not need to give cgminer any
    arguments and it will load your configuration.
    
    Any configuration file may also contain a single
    	"include" : "filename"
    to recursively include another configuration file.
    Writing the configuration will save all settings from all files in the output.
    
    
    Single pool, regular desktop:
    
    cgminer -o http://pool:port -u username -p password
    
    Single pool, dedicated miner:
    
    cgminer -o http://pool:port -u username -p password -I 9
    
    Single pool, first card regular desktop, 3 other dedicated cards:
    
    cgminer -o http://pool:port -u username -p password -I d,9,9,9
    
    Multiple pool, dedicated miner:
    
    cgminer -o http://pool1:port -u pool1username -p pool1password -o http://pool2:port -u pool2usernmae -p pool2password -I 9
    
    Add overclocking settings, GPU and fan control for all cards:
    
    cgminer -o http://pool:port -u username -p password -I 9 --auto-fan --auto-gpu --gpu-engine 750-950 --gpu-memclock 300
    
    Add overclocking settings, GPU and fan control with different engine settings for 4 cards:
    
    cgminer -o http://pool:port -u username -p password -I 9 --auto-fan --auto-gpu --gpu-engine 750-950,945,700-930,960 --gpu-memclock 300
    
    Single pool with a standard http proxy, regular desktop:
    
    cgminer -o "http:proxy:port|http://pool:port" -u username -p password
    
    Single pool with a socks5 proxy, regular desktop:
    
    cgminer -o "socks5:proxy:port|http://pool:port" -u username -p password
    
    Single pool with stratum protocol support:
    
    cgminer -o stratum+tcp://pool:port -u username -p password
    
    The list of proxy types are:
     http:    standard http 1.1 proxy
     http0:   http 1.0 proxy
     socks4:  socks4 proxy
     socks5:  socks5 proxy
     socks4a: socks4a proxy
     socks5h: socks5 proxy using a hostname
    
    If you compile cgminer with a version of CURL before 7.19.4 then some of the above will
    not be available. All are available since CURL version 7.19.4
    
    If you specify the --socks-proxy option to cgminer, it will only be applied to all pools
    that don't specify their own proxy setting like above
    
    READ WARNINGS AND DOCUMENTATION BELOW ABOUT OVERCLOCKING
    
    To configure multiple displays on linux you need to configure your Xorg cleanly
    to use them all:
    
    sudo aticonfig --adapter=all -f --initial
    
    On Linux you virtually always need to export your display settings before
    starting to get all the cards recognised and/or temperature+clocking working:
    
    export DISPLAY=:0
    
    ---
    BUILDING CGMINER
    
    Dependencies:
    	curl dev library 	http://curl.haxx.se/libcurl/
    	(libcurl4-openssl-dev)
    
    	curses dev library
    	(libncurses5-dev or libpdcurses on WIN32)
    
    	pkg-config		http://www.freedesktop.org/wiki/Software/pkg-config
    	libtool			http://www.gnu.org/software/libtool/
    
    	jansson			http://www.digip.org/jansson/
    	(jansson is included in-tree and not necessary)
    
    	AMD APP SDK		http://developer.amd.com/sdks/AMDAPPSDK
    	(This sdk is mandatory for GPU mining)
    
    	AMD ADL SDK		http://developer.amd.com/sdks/ADLSDK
    	(This sdk is mandatory for ATI GPU monitoring & clocking)
    
    	libudev headers
    	(This is only required for FPGA auto-detection and is linux only)
    
    	libusb headers
    	(This is only required for ZTEX and ModMiner support)
    
    
    CGMiner specific configuration options:
    	--disable-opencl        Override detection and disable building with opencl
    	--disable-adl           Override detection and disable building with adl
    	--enable-bitforce       Compile support for BitForce FPGAs(default disabled)
    	--enable-icarus         Compile support for Icarus Board(default disabled)
    	--enable-modminer       Compile support for ModMiner FPGAs(default disabled)
    	--enable-ztex           Compile support for Ztex Board(default disabled)
    	--enable-scrypt         Compile support for scrypt litecoin mining (default disabled)
    	--without-curses        Compile support for curses TUI (default enabled)
    	--without-libudev       Autodetect FPGAs using libudev (default enabled)
    
    Basic *nix build instructions:
    	To build with GPU mining support:
    	Install AMD APP sdk, ideal version (see FAQ!) - no official place to
    	install it so just keep track of where it is if you're not installing
    	the include files and library files into the system directory.
    	(Do NOT install the ati amd sdk if you are on nvidia.)
    	To build with GPU monitoring & clocking support:
    	Extract the AMD ADL SDK, latest version - there is also no official
    	place for these files. Copy all the *.h files in the "include"
    	directory into cgminer's ADL_SDK directory.
    
    The easiest way to install the ATI AMD SPP sdk on linux is to actually put it
    into a system location. Then building will be simpler. Download the correct
    version for either 32 bit or 64 bit from here:
    	http://developer.amd.com/tools/heterogeneous-computing/amd-accelerated-parallel-processing-app-sdk/downloads/
    
    The best version for Radeon 5xxx and 6xxx is v2.5, while 7xxx cards need
    v2.6 or later, 2.7 seems the best.
    
    For versions 2.4 or earlier you will need to manually install them:
    This will give you a file with a name like:
     AMD-APP-SDK-v2.4-lnx64.tgz (64-bit)
    or
     AMD-APP-SDK-v2.4-lnx32.tgz (32-bit)
    
    Then:
    
    sudo su
    cd /opt
    tar xf /path/to/AMD-APP-SDK-v2.4-lnx##.tgz
    cd /
    tar xf /opt/AMD-APP-SDK-v2.4-lnx##/icd-registration.tgz
    ln -s /opt/AMD-APP-SDK-v2.4-lnx##/include/CL /usr/include
    ln -s /opt/AMD-APP-SDK-v2.4-lnx##/lib/x86_64/* /usr/lib/
    ldconfig
    
    Where ## is 32 or 64, depending on the bitness of the SDK you downloaded.
    If you are on 32 bit, x86_64 in the 2nd last line should be x86
    
    	To actually build:
    
    	./autogen.sh	# only needed if building from git repo
    	CFLAGS="-O2 -Wall -march=native" ./configure
    	or if you haven't installed the ati files in system locations:
    	CFLAGS="-O2 -Wall -march=native -I<path to AMD APP include>" LDFLAGS="-L<path to AMD APP lib/x86_64> ./configure
    	make
    	
    	If it finds the opencl files it will inform you with
    	"OpenCL: FOUND. GPU mining support enabled."
    
    Native WIN32 build instructions: see windows-build.txt
    
    ---
    
    Usage instructions:  Run "cgminer --help" to see options:
    
    Usage: . [-atDdGCgIKklmpPQqrRsTouvwOchnV] 
    Options for both config file and command line:
    --api-allow         Allow API access (if enabled) only to the given list of [W:]IP[/Prefix] address[/subnets]
                        This overrides --api-network and you must specify 127.0.0.1 if it is required
                        W: in front of the IP address gives that address privileged access to all api commands
    --api-description   Description placed in the API status header (default: cgminer version)
    --api-groups        API one letter groups G:cmd:cmd[,P:cmd:*...]
                        See API-README for usage
    --api-listen        Listen for API requests (default: disabled)
                        By default any command that does not just display data returns access denied
                        See --api-allow to overcome this
    --api-network       Allow API (if enabled) to listen on/for any address (default: only 127.0.0.1)
    --api-port          Port number of miner API (default: 4028)
    --auto-fan          Automatically adjust all GPU fan speeds to maintain a target temperature
    --auto-gpu          Automatically adjust all GPU engine clock speeds to maintain a target temperature
    --balance           Change multipool strategy from failover to even share balance
    --benchmark         Run cgminer in benchmark mode - produces no shares
    --compact           Use compact display without per device statistics
    --debug|-D          Enable debug output
    --disable-rejecting Automatically disable pools that continually reject shares
    --expiry|-E <arg>   Upper bound on how many seconds after getting work we consider a share from it stale (default: 120)
    --failover-only     Don't leak work to backup pools when primary pool is lagging
    --fix-protocol      Do not redirect to a different getwork protocol (eg. stratum)
    --hotplug <arg>     Set hotplug check time to <arg> seconds (0=never default: 5) - only with libusb
    --kernel-path|-K <arg> Specify a path to where bitstream and kernel files are (default: "/usr/local/bin")
    --load-balance      Change multipool strategy from failover to efficiency based balance
    --log|-l <arg>      Interval in seconds between log output (default: 5)
    --monitor|-m <arg>  Use custom pipe cmd for output messages
    --net-delay         Impose small delays in networking to not overload slow routers
    --no-submit-stale   Don't submit shares if they are detected as stale
    --pass|-p <arg>     Password for bitcoin JSON-RPC server
    --per-device-stats  Force verbose mode and output per-device statistics
    --protocol-dump|-P  Verbose dump of protocol-level activities
    --queue|-Q <arg>    Minimum number of work items to have queued (0 - 10) (default: 1)
    --quiet|-q          Disable logging output, display status and errors
    --real-quiet        Disable all output
    --remove-disabled   Remove disabled devices entirely, as if they didn't exist
    --rotate <arg>      Change multipool strategy from failover to regularly rotate at N minutes (default: 0)
    --round-robin       Change multipool strategy from failover to round robin on failure
    --scan-time|-s <arg> Upper bound on time spent scanning current work, in seconds (default: 60)
    --sched-start <arg> Set a time of day in HH:MM to start mining (a once off without a stop time)
    --sched-stop <arg>  Set a time of day in HH:MM to stop mining (will quit without a start time)
    --scrypt            Use the scrypt algorithm for mining (litecoin only)
    --sharelog <arg>    Append share log to file
    --shares <arg>      Quit after mining N shares (default: unlimited)
    --socks-proxy <arg> Set socks4 proxy (host:port) for all pools without a proxy specified
    --syslog            Use system log for output messages (default: standard error)
    --temp-cutoff <arg> Temperature where a device will be automatically disabled, one value or comma separated list (default: 95)
    --text-only|-T      Disable ncurses formatted screen output
    --url|-o <arg>      URL for bitcoin JSON-RPC server
    --user|-u <arg>     Username for bitcoin JSON-RPC server
    --verbose           Log verbose output to stderr as well as status output
    --userpass|-O <arg> Username:Password pair for bitcoin JSON-RPC server
    Options for command line only:
    --config|-c <arg>   Load a JSON-format configuration file
    See example.conf for an example configuration.
    --help|-h           Print this message
    --version|-V        Display version and exit
    
    
    GPU only options:
    
    --auto-fan          Automatically adjust all GPU fan speeds to maintain a target temperature
    --auto-gpu          Automatically adjust all GPU engine clock speeds to maintain a target temperature
    --device|-d <arg>   Select device to use, (Use repeat -d for multiple devices, default: all)
    --disable-gpu|-G    Disable GPU mining even if suitable devices exist
    --gpu-threads|-g <arg> Number of threads per GPU (1 - 10) (default: 2)
    --gpu-dyninterval <arg> Set the refresh interval in ms for GPUs using dynamic intensity (default: 7)
    --gpu-engine <arg>  GPU engine (over)clock range in Mhz - one value, range and/or comma separated list (e.g. 850-900,900,750-850)
    --gpu-fan <arg>     GPU fan percentage range - one value, range and/or comma separated list (e.g. 25-85,85,65)
    --gpu-map <arg>     Map OpenCL to ADL device order manually, paired CSV (e.g. 1:0,2:1 maps OpenCL 1 to ADL 0, 2 to 1)
    --gpu-memclock <arg> Set the GPU memory (over)clock in Mhz - one value for all or separate by commas for per card.
    --gpu-memdiff <arg> Set a fixed difference in clock speed between the GPU and memory in auto-gpu mode
    --gpu-powertune <arg> Set the GPU powertune percentage - one value for all or separate by commas for per card.
    --gpu-reorder       Attempt to reorder GPU devices according to PCI Bus ID
    --gpu-vddc <arg>    Set the GPU voltage in Volts - one value for all or separate by commas for per card.
    --intensity|-I <arg> Intensity of GPU scanning (d or -10 -> 10, default: d to maintain desktop interactivity)
    --kernel|-k <arg>   Override kernel to use (diablo, poclbm, phatk or diakgcn) - one value or comma separated
    --ndevs|-n          Enumerate number of detected GPUs and exit
    --no-restart        Do not attempt to restart GPUs that hang
    --temp-hysteresis <arg> Set how much the temperature can fluctuate outside limits when automanaging speeds (default: 3)
    --temp-overheat <arg> Overheat temperature when automatically managing fan and GPU speeds (default: 85)
    --temp-target <arg> Target temperature when automatically managing fan and GPU speeds (default: 75)
    --vectors|-v <arg>  Override detected optimal vector (1, 2 or 4) - one value or comma separated list
    --worksize|-w <arg> Override detected optimal worksize - one value or comma separated list
    
    
    SCRYPT only options:
    
    --lookup-gap <arg>  Set GPU lookup gap for scrypt mining, comma separated
    --shaders <arg>     GPU shaders per card for tuning scrypt, comma separated
    --thread-concurrency <arg> Set GPU thread concurrency for scrypt mining, comma separated
    
    See SCRYPT-README for more information regarding litecoin mining.
    
    
    ASIC and FPGA mining boards (BFL ASIC, BitForce, Icarus, ModMiner, Ztex)
    only options:
    
    Cgminer will automatically find all of your BFL ASIC, BitForce FPGAs,
    ModMiner FPGAs or Ztex FPGAs
    The --usb option can restrict how many BFL ASIC, BitForce FPGAs or
    ModMiner FPGAs it finds:
    
      --usb 1:2,1:3,1:4,1:*
    or
      --usb BAS:1,BFL:1,MMQ:0
    or
      --usb :10
    
    You can only use one of the above 3
    
    The first version
      --usb 1:2,1:3,1:4,1:*
    allows you to select which devices to mine on with a list of USB
     bus_number:device_address
    All other USB devices will be ignored
    Hotplug will also only look at the devices matching the list specified and
    find nothing new if they are all in use
    You can specify just the USB bus_number to find all devices like 1:*
    which means any devices on USB bus_number 1
    This is useful if you unplug a device then plug it back in the same port,
    it usually reappears with the same bus_number but a different device_address
    
    You can see the list of all USB devices on linux with 'sudo lsusb'
    Cgminer will list the recognised USB devices with the '--usb-dump 0' option
    The '--usb-dump N' option with a value of N greater than 0 will dump a lot
    of details about each recognised USB device
    If you wish to see all USB devices, include the --usb-list-all option
    
    The second version
      --usb BAS:1,BFL:1,MMQ:0
    allows you to specify how many devices to choose based on each device
    driver cgminer has - there are currently 3 USB drivers: BAS, BFL & MMQ
    N.B. you can only specify which device driver to limit, not the type of
    each device, e.g. with BAS:n you can limit how many BFL ASIC devices will
    be checked, but you cannot limit the number of each type of BFL ASIC
    Also note that the MMQ count is the number of MMQ backplanes you have
    not the number of MMQ FPGAs
    
    The third version
      --usb :10
    means only use a maximum of 10 devices of any supported USB devices
    Once cgminer has 10 devices it will not configure any more and hotplug will
    not scan for any more
    If one of the 10 devices stops working, hotplug - if enabled, as is default
    - will scan normally again until it has 10 devices
    
    
    --scan-serial|-S <arg> Serial port to probe for Icarus mining device
    
    This option is only for Icarus bitstream FPGAs
    
    By default, cgminer will scan for autodetected Icarus unless at least one
    -S is specified for that driver. If you specify -S and still want cgminer
    to scan, you must also use "-S auto". If you want to prevent cgminer from
    scanning without specifying a device, you can use "-S noauto". Note that
    presently, autodetection only works on Linux, and might only detect one
    device depending on the version of udev being used.
    
    On linux <arg> is usually of the format /dev/ttyUSBn
    On windows <arg> is usually of the format \\.\COMn
    (where n = the correct device number for the Icarus device)
    
    The official supplied binaries are compiled with support for all FPGAs.
    To force the code to only attempt detection with a specific driver,
    prepend the argument with the driver name followed by a colon.
    For example, "icarus:/dev/ttyUSB0" or using the short name: "ica:/dev/ttyUSB0"
    This option not longer matters since Icarus is the only serial-USB
    device that uses it
    
    For other FPGA details see the FPGA-README
    
    
    ---
    
    WHILE RUNNING:
    
    The following options are available while running with a single keypress:
    
    [P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit
    
    P gives you:
    
    Current pool management strategy: Failover
    [F]ailover only disabled
    [A]dd pool [R]emove pool [D]isable pool [E]nable pool
    [C]hange management strategy [S]witch pool [I]nformation
    
    
    S gives you:
    
    [Q]ueue: 1
    [S]cantime: 60
    [E]xpiry: 120
    [W]rite config file
    [C]gminer restart
    
    
    D gives you:
    
    [N]ormal [C]lear [S]ilent mode (disable all output)
    [D]ebug:off
    [P]er-device:off
    [Q]uiet:off
    [V]erbose:off
    [R]PC debug:off
    [W]orkTime details:off
    co[M]pact: off
    [L]og interval:5
    
    
    Q quits the application.
    
    
    G gives you something like:
    
    GPU 0: [124.2 / 191.3 Mh/s] [A:77  R:33  HW:0  U:1.73/m  WU 1.73/m]
    Temp: 67.0 C
    Fan Speed: 35% (2500 RPM)
    Engine Clock: 960 MHz
    Memory Clock: 480 Mhz
    Vddc: 1.200 V
    Activity: 93%
    Powertune: 0%
    Last initialised: [2011-09-06 12:03:56]
    Thread 0: 62.4 Mh/s Enabled ALIVE
    Thread 1: 60.2 Mh/s Enabled ALIVE
    
    [E]nable [D]isable [R]estart GPU [C]hange settings
    Or press any other key to continue
    
    
    The running log shows output like this:
    
     [2012-10-12 18:02:20] Accepted f0c05469 Diff 1/1 GPU 0 pool 1
     [2012-10-12 18:02:22] Accepted 218ac982 Diff 7/1 GPU 1 pool 1
     [2012-10-12 18:02:23] Accepted d8300795 Diff 1/1 GPU 3 pool 1
     [2012-10-12 18:02:24] Accepted 122c1ff1 Diff 14/1 GPU 1 pool 1
    
    The 8 byte hex value are the 2nd 8 bytes of the share being submitted to the
    pool. The 2 diff values are the actual difficulty target that share reached
    followed by the difficulty target the pool is currently asking for.
    
    ---
    Also many issues and FAQs are covered in the forum thread
    dedicated to this program,
    	http://forum.bitcoin.org/index.php?topic=28402.0
    
    The output line shows the following:
    (5s):1713.6 (avg):1707.8 Mh/s | A:729  R:8  HW:0  U:22.53/m  WU:22.53/m
    
    Each column is as follows:
    5s:  A 5 second exponentially decaying average hash rate
    avg: An all time average hash rate
    A:   The number of Accepted shares
    R:   The number of Rejected shares
    HW:  The number of HardWare errors
    U:   The Utility defined as the number of shares / minute
    WU:  The Work Utility defined as the number of diff1 shares work / minute
         (accepted or rejected).
    
     GPU 1: 73.5C 2551RPM | 427.3/443.0Mh/s | A:8 R:0 HW:0 U:4.39/m
    
    Each column is as follows:
    Temperature (if supported)
    Fanspeed (if supported)
    A 5 second exponentially decaying average hash rate
    An all time average hash rate
    The number of accepted shares
    The number of rejected shares
    The number of hardware erorrs
    The utility defines as the number of shares / minute
    
    The cgminer status line shows:
     ST: 1  SS: 0  NB: 1  LW: 8  GF: 1  RF: 1  WU:4.4/m
    
    ST is STaged work items (ready to use).
    SS is Stale Shares discarded (detected and not submitted so don't count as rejects)
    NB is New Blocks detected on the network
    LW is Locally generated Work items
    GF is Getwork Fail Occasions (server slow to provide work)
    RF is Remote Fail occasions (server slow to accept work)
    WU is Work Utility (Rate of difficulty 1 shares solved per minute)
    
    NOTE: Running intensities above 9 with current hardware is likely to only
    diminish return performance even if the hash rate might appear better. A good
    starting baseline intensity to try on dedicated miners is 9. 11 is the upper
    limit for intensity while BTC mining, if the GPU_USE_SYNC_OBJECTS variable
    is set (see FAQ). The upper limit for sha256 mining is 14 and 20 for scrypt.
    
    
    The block display shows:
    Block: 0074c5e482e34a506d2a051a...  Started: [17:17:22]  Best share: 2.71K
    
    This shows a short stretch of the current block, when the new block started,
    and the all time best difficulty share you've found since starting cgminer
    this time.
    
    
    ---
    MULTIPOOL
    
    FAILOVER STRATEGIES WITH MULTIPOOL:
    A number of different strategies for dealing with multipool setups are
    available. Each has their advantages and disadvantages so multiple strategies
    are available by user choice, as per the following list:
    
    FAILOVER:
    The default strategy is failover. This means that if you input a number of
    pools, it will try to use them as a priority list, moving away from the 1st
    to the 2nd, 2nd to 3rd and so on. If any of the earlier pools recover, it will
    move back to the higher priority ones.
    
    ROUND ROBIN:
    This strategy only moves from one pool to the next when the current one falls
    idle and makes no attempt to move otherwise.
    
    ROTATE:
    This strategy moves at user-defined intervals from one active pool to the next,
    skipping pools that are idle.
    
    LOAD BALANCE:
    This strategy sends work to all the pools to maintain optimum load. The most
    efficient pools will tend to get a lot more shares. If any pool falls idle, the
    rest will tend to take up the slack keeping the miner busy.
    
    BALANCE:
    This strategy monitors the amount of difficulty 1 shares solved for each pool
    and uses it to try to end up doing the same amount of work for all pools.
    
    
    ---
    LOGGING
    
    cgminer will log to stderr if it detects stderr is being redirected to a file.
    To enable logging simply add 2>logfile.txt to your command line and logfile.txt
    will contain the logged output at the log level you specify (normal, verbose,
    debug etc.)
    
    In other words if you would normally use:
    ./cgminer -o xxx -u yyy -p zzz
    if you use
    ./cgminer -o xxx -u yyy -p zzz 2>logfile.txt
    it will log to a file called logfile.txt and otherwise work the same.
    
    There is also the -m option on linux which will spawn a command of your choice
    and pipe the output directly to that command.
    
    The WorkTime details 'debug' option adds details on the end of each line
    displayed for Accepted or Rejected work done. An example would be:
    
     <-00000059.ed4834a3 M:X D:1.0 G:17:02:38:0.405 C:1.855 (2.995) W:3.440 (0.000) S:0.461 R:17:02:47
    
    The first 2 hex codes are the previous block hash, the rest are reported in
    seconds unless stated otherwise:
    The previous hash is followed by the getwork mode used M:X where X is one of
    P:Pool, T:Test Pool, L:LP or B:Benchmark,
    then D:d.ddd is the difficulty required to get a share from the work,
    then G:hh:mm:ss:n.nnn, which is when the getwork or LP was sent to the pool and
    the n.nnn is how long it took to reply,
    followed by 'O' on it's own if it is an original getwork, or 'C:n.nnn' if it was
    a clone with n.nnn stating how long after the work was recieved that it was cloned,
    (m.mmm) is how long from when the original work was received until work started,
    W:n.nnn is how long the work took to process until it was ready to submit,
    (m.mmm) is how long from ready to submit to actually doing the submit, this is
    usually 0.000 unless there was a problem with submitting the work,
    S:n.nnn is how long it took to submit the completed work and await the reply,
    R:hh:mm:ss is the actual time the work submit reply was received
    
    If you start cgminer with the --sharelog option, you can get detailed
    information for each share found. The argument to the option may be "-" for
    standard output (not advisable with the ncurses UI), any valid positive number
    for that file descriptor, or a filename.
    
    To log share data to a file named "share.log", you can use either:
    ./cgminer --sharelog 50 -o xxx -u yyy -p zzz 50>share.log
    ./cgminer --sharelog share.log -o xxx -u yyy -p zzz
    
    For every share found, data will be logged in a CSV (Comma Separated Value)
    format:
        timestamp,disposition,target,pool,dev,thr,sharehash,sharedata
    For example (this is wrapped, but it's all on one line for real):
        1335313090,reject,
        ffffffffffffffffffffffffffffffffffffffffffffffffffffffff00000000,
        http://localhost:8337,GPU0,0,
        6f983c918f3299b58febf95ec4d0c7094ed634bc13754553ec34fc3800000000,
        00000001a0980aff4ce4a96d53f4b89a2d5f0e765c978640fe24372a000001c5
        000000004a4366808f81d44f26df3d69d7dc4b3473385930462d9ab707b50498
        f681634a4f1f63d01a0cd43fb338000000000080000000000000000000000000
        0000000000000000000000000000000000000000000000000000000080020000
    
    ---
    OVERCLOCKING WARNING AND INFORMATION
    
    AS WITH ALL OVERCLOCKING TOOLS YOU ARE ENTIRELY RESPONSIBLE FOR ANY HARM YOU
    MAY CAUSE TO YOUR HARDWARE. OVERCLOCKING CAN INVALIDATE WARRANTIES, DAMAGE
    HARDWARE AND EVEN CAUSE FIRES. THE AUTHOR ASSUMES NO RESPONSIBILITY FOR ANY
    DAMAGE YOU MAY CAUSE OR UNPLANNED CHILDREN THAT MAY OCCUR AS A RESULT.
    
    The GPU monitoring, clocking and fanspeed control incorporated into cgminer
    comes through use of the ATI Display Library. As such, it only supports ATI
    GPUs. Even if ADL support is successfully built into cgminer, unless the card
    and driver supports it, no GPU monitoring/settings will be available.
    
    Cgminer supports initial setting of GPU engine clock speed, memory clock
    speed, voltage, fanspeed, and the undocumented powertune feature of 69x0+ GPUs.
    The setting passed to cgminer is used by all GPUs unless separate values are
    specified. All settings can all be changed within the menu on the fly on a
    per-GPU basis.
    
    For example:
    --gpu-engine 950 --gpu-memclock 825
    
    will try to set all GPU engine clocks to 950 and all memory clocks to 825,
    while:
    --gpu-engine 950,945,930,960 --gpu-memclock 300
    
    will try to set the engine clock of card 0 to 950, 1 to 945, 2 to 930, 3 to
    960 and all memory clocks to 300.
    
    AUTO MODES:
    There are two "auto" modes in cgminer, --auto-fan and --auto-gpu. These can
    be used independently of each other and are complementary. Both auto modes
    are designed to safely change settings while trying to maintain a target
    temperature. By default this is set to 75 degrees C but can be changed with:
    
    --temp-target
    e.g.
    --temp-target 80
    Sets all cards' target temperature to 80 degrees.
    
    --temp-target 75,85
    Sets card 0 target temperature to 75, and card 1 to 85 degrees.
    
    AUTO FAN:
    e.g.
    --auto-fan (implies 85% upper limit)
    --gpu-fan 25-85,65 --auto-fan
    
    Fan control in auto fan works off the theory that the minimum possible fan
    required to maintain an optimal temperature will use less power, make less
    noise, and prolong the life of the fan. In auto-fan mode, the fan speed is
    limited to 85% if the temperature is below "overheat" intentionally, as
    higher fanspeeds on GPUs do not produce signficantly more cooling, yet
    significanly shorten the lifespan of the fans. If temperature reaches the
    overheat value, fanspeed will still be increased to 100%. The overheat value
    is set to 85 degrees by default and can be changed with:
    
    --temp-overheat
    e.g.
    --temp-overheat 75,85
    Sets card 0 overheat threshold to 75 degrees and card 1 to 85.
    
    AUTO GPU:
    e.g.
    --auto-gpu --gpu-engine 750-950
    --auto-gpu --gpu-engine 750-950,945,700-930,960
    
    GPU control in auto gpu tries to maintain as high a clock speed as possible
    while not reaching overheat temperatures. As a lower clock speed limit,
    the auto-gpu mode checks the GPU card's "normal" clock speed and will not go
    below this unless you have manually set a lower speed in the range. Also,
    unless a higher clock speed was specified at startup, it will not raise the
    clockspeed. If the temperature climbs, fanspeed is adjusted and optimised
    before GPU engine clockspeed is adjusted. If fan speed control is not available
    or already optimal, then GPU clock speed is only decreased if it goes over
    the target temperature by the hysteresis amount, which is set to 3 by default
    and can be changed with:
    --temp-hysteresis
    If the temperature drops below the target temperature, and engine clock speed
    is not at the highest level set at startup, cgminer will raise the clock speed.
    If at any time you manually set an even higher clock speed successfully in
    cgminer, it will record this value and use it as its new upper limit (and the
    same for low clock speeds and lower limits). If the temperature goes over the
    cutoff limit (95 degrees by default), cgminer will completely disable the GPU
    from mining and it will not be re-enabled unless manually done so. The cutoff
    temperature can be changed with:
    
    --temp-cutoff
    e.g.
    --temp-cutoff 95,105
    Sets card 0 cutoff temperature to 95 and card 1 to 105.
    
    --gpu-memdiff -125
    This setting will modify the memory speed whenever the GPU clock speed is
    modified by --auto-gpu. In this example, it will set the memory speed to
    be 125 Mhz lower than the GPU speed. This is useful for some cards like the
    6970 which normally don't allow a bigger clock speed difference. The 6970 is
    known to only allow -125, while the 7970 only allows -150.
    
    
    CHANGING SETTINGS:
    When setting values, it is important to realise that even though the driver
    may report the value was changed successfully, and the new card power profile
    information contains the values you set it to, that the card itself may
    refuse to use those settings. As the performance profile changes dynamically,
    querying the "current" value on the card can be wrong as well. So when changing
    values in cgminer, after a pause of 1 second, it will report to you the current
    values where you should check that your change has taken. An example is that
    6970 reference cards will accept low memory values but refuse to actually run
    those lower memory values unless they're within 125 of the engine clock speed.
    In that scenario, they usually set their real speed back to their default.
    
    Cgminer reports the so-called "safe" range of whatever it is you are modifying
    when you ask to modify it on the fly. However, you can change settings to values
    outside this range. Despite this, the card can easily refuse to accept your
    changes, or worse, to accept your changes and then silently ignore them. So
    there is absolutely to know how far to/from where/to it can set things safely or
    otherwise, and there is nothing stopping you from at least trying to set them
    outside this range. Being very conscious of these possible failures is why
    cgminer will report back the current values for you to examine how exactly the
    card has responded. Even within the reported range of accepted values by the
    card, it is very easy to crash just about any card, so it cannot use those
    values to determine what range to set. You have to provide something meaningful
    manually for cgminer to work with through experimentation.
    
    STARTUP / SHUTDOWN:
    When cgminer starts up, it tries to read off the current profile information
    for clock and fan speeds and stores these values. When quitting cgminer, it
    will then try to restore the original values. Changing settings outside of
    cgminer while it's running may be reset to the startup cgminer values when
    cgminer shuts down because of this.
    
    ---
    
    RPC API
    
    For RPC API details see the API-README file
    
    ---
    
    GPU DEVICE ISSUES and use of --gpu-map
    
    GPUs mine with OpenCL software via the GPU device driver. This means you need
    to have both an OpenCL SDK installed, and the GPU device driver RUNNING (i.e.
    Xorg up and running configured for all devices that will mine on linux etc.)
    Meanwhile, the hardware monitoring that cgminer offers for AMD devices relies
    on the ATI Display Library (ADL) software to work. OpenCL DOES NOT TALK TO THE
    ADL. There is no 100% reliable way to know that OpenCL devices are identical
    to the ADL devices, as neither give off the same information. cgminer does its
    best to correlate these devices based on the order that OpenCL and ADL numbers
    them. It is possible that this will fail for the following reasons:
    
    1. The device order is listed differently by OpenCL and ADL (rare), even if the
    number of devices is the same.
    2. There are more OpenCL devices than ADL. OpenCL stupidly sees one GPU as two
    devices if you have two monitors connected to the one GPU.
    3. There are more ADL devices than OpenCL. ADL devices include any ATI GPUs,
    including ones that can't mine, like some older R4xxx cards.
    
    To cope with this, the ADVANCED option for --gpu-map is provided with cgminer.
    DO NOT USE THIS UNLESS YOU KNOW WHAT YOU ARE DOING. The default will work the
    vast majority of the time unless you know you have a problem already.
    
    To get useful information, start cgminer with just the -n option. You will get
    output that looks like this:
    
    [2012-04-25 13:17:34] CL Platform 0 vendor: Advanced Micro Devices, Inc.
    [2012-04-25 13:17:34] CL Platform 0 name: AMD Accelerated Parallel Processing
    [2012-04-25 13:17:34] CL Platform 0 version: OpenCL 1.1 AMD-APP (844.4)
    [2012-04-25 13:17:34] Platform 0 devices: 3
    [2012-04-25 13:17:34]   0       Tahiti
    [2012-04-25 13:17:34]   1       Tahiti
    [2012-04-25 13:17:34]   2       Cayman
    [2012-04-25 13:17:34] GPU 0 AMD Radeon HD 7900 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 1 AMD Radeon HD 7900 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 2 AMD Radeon HD 6900 Series hardware monitoring enabled
    [2012-04-25 13:17:34] 3 GPU devices max detected
    
    Note the number of devices here match, and the order is the same. If devices 1
    and 2 were different between Tahiti and Cayman, you could run cgminer with:
    --gpu-map 2:1,1:2
    And it would swap the monitoring it received from ADL device 1 and put it to
    opencl device 2 and vice versa.
    
    If you have 2 monitors connected to the first device it would look like this:
    
    [2012-04-25 13:17:34] Platform 0 devices: 4
    [2012-04-25 13:17:34]   0       Tahiti
    [2012-04-25 13:17:34]   1       Tahiti
    [2012-04-25 13:17:34]   2       Tahiti
    [2012-04-25 13:17:34]   3       Cayman
    [2012-04-25 13:17:34] GPU 0 AMD Radeon HD 7900 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 1 AMD Radeon HD 7900 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 2 AMD Radeon HD 6900 Series hardware monitoring enabled
    
    To work around this, you would use:
    -d 0 -d 2 -d 3 --gpu-map 2:1,3:2
    
    If you have an older card as well as the rest it would look like this:
    
    [2012-04-25 13:17:34] Platform 0 devices: 3
    [2012-04-25 13:17:34]   0       Tahiti
    [2012-04-25 13:17:34]   1       Tahiti
    [2012-04-25 13:17:34]   2       Cayman
    [2012-04-25 13:17:34] GPU 0 AMD Radeon HD 4500 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 1 AMD Radeon HD 7900 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 2 AMD Radeon HD 7900 Series  hardware monitoring enabled
    [2012-04-25 13:17:34] GPU 3 AMD Radeon HD 6900 Series hardware monitoring enabled
    
    To work around this you would use:
    --gpu-map 0:1,1:2,2:3
    
    
    ---
    
    FAQ
    
    Q: cgminer segfaults when I change my shell window size.
    A: Older versions of libncurses have a bug to do with refreshing a window
    after a size change. Upgrading to a new version of curses will fix it.
    
    Q: Can I mine on servers from different networks (eg smartcoin and bitcoin) at
    the same time?
    A: No, cgminer keeps a database of the block it's working on to ensure it does
    not work on stale blocks, and having different blocks from two networks would
    make it invalidate the work from each other.
    
    Q: Can I change the intensity settings individually for each GPU?
    A: Yes, pass a list separated by commas such as -I d,4,9,9
    
    Q: Can I put multiple pools in the config file?
    A: Yes, check the example.conf file. Alternatively, set up everything either on
    the command line or via the menu after startup and choose settings->write
    config file and the file will be loaded one each startup.
    
    Q: The build fails with gcc is unable to build a binary.
    A: Remove the "-march=native" component of your CFLAGS as your version of gcc
    does not support it.
    
    Q: The CPU usage is high.
    A: The ATI drivers after 11.6 have a bug that makes them consume 100% of one
    CPU core unnecessarily so downgrade to 11.6. Binding cgminer to one CPU core on
    windows can minimise it to 100% (instead of more than one core). Driver version
    11.11 on linux and 11.12 on windows appear to have fixed this issue. Note that
    later drivers may have an apparent return of high CPU usage. Try
    'export GPU_USE_SYNC_OBJECTS=1' on Linux before starting cgminer. You can also
    set this variable in windows via a batch file or on the command line before
    starting cgminer with 'setx GPU_USE_SYNC_OBJECTS 1'
    
    Q: Can you implement feature X?
    A: I can, but time is limited, and people who donate are more likely to get
    their feature requests implemented.
    
    Q: My GPU hangs and I have to reboot it to get it going again?
    A: The more aggressively the mining software uses your GPU, the less overclock
    you will be able to run. You are more likely to hit your limits with cgminer
    and you will find you may need to overclock your GPU less aggressively. The
    software cannot be responsible and make your GPU hang directly. If you simply
    cannot get it to ever stop hanging, try decreasing the intensity, and if even
    that fails, try changing to the poclbm kernel with -k poclbm, though you will
    sacrifice performance. cgminer is designed to try and safely restart GPUs as
    much as possible, but NOT if that restart might actually crash the rest of the
    GPUs mining, or even the machine. It tries to restart them with a separate
    thread and if that separate thread dies, it gives up trying to restart any more
    GPUs.
    
    Q: Work keeps going to my backup pool even though my primary pool hasn't
    failed?
    A: Cgminer checks for conditions where the primary pool is lagging and will
    pass some work to the backup servers under those conditions. The reason for
    doing this is to try its absolute best to keep the GPUs working on something
    useful and not risk idle periods. You can disable this behaviour with the
    option --failover-only.
    
    Q: Is this a virus?
    A: Cgminer is being packaged with other trojan scripts and some antivirus
    software is falsely accusing cgminer.exe as being the actual virus, rather
    than whatever it is being packaged with. If you installed cgminer yourself,
    then you do not have a virus on your computer. Complain to your antivirus
    software company. They seem to be flagging even source code now from cgminer
    as viruses, even though text source files can't do anything by themself.
    
    Q: Can you modify the display to include more of one thing in the output and
    less of another, or can you change the quiet mode or can you add yet another
    output mode?
    A: Everyone will always have their own view of what's important to monitor.
    The defaults are very sane and I have very little interest in changing this
    any further.
    
    Q: Can you change the autofan/autogpu to change speeds in a different manner?
    A: The defaults are sane and safe. I'm not interested in changing them
    further. The starting fan speed is set to 50% in auto-fan mode as a safety
    precaution.
    
    Q: What are the best parameters to pass for X pool/hardware/device.
    A: Virtually always, the DEFAULT parameters give the best results. Most user
    defined settings lead to worse performance. The ONLY thing most users should
    need to set is the Intensity.
    
    Q: What happened to CPU mining?
    A: Being increasingly irrelevant for most users, and a maintenance issue, it is
    no longer under active development and will not be supported. No binary builds
    supporting CPU mining will be released. Virtually all remaining users of CPU
    mining are as back ends for illegal botnets.
    
    Q: I upgraded cgminer version and my hashrate suddenly dropped!
    A: No, you upgraded your SDK version unwittingly between upgrades of cgminer
    and that caused  your hashrate to drop. See the next question.
    
    Q: I upgraded my ATI driver/SDK/cgminer and my hashrate suddenly dropped!
    A: The hashrate performance in cgminer is tied to the version of the ATI SDK
    that is installed only for the very first time cgminer is run. This generates
    binaries that are used by the GPU every time after that. Any upgrades to the
    SDK after that time will have no effect on the binaries. However, if you
    install a fresh version of cgminer, and have since upgraded your SDK, new
    binaries will be built. It is known that the 2.6 ATI SDK has a huge hashrate
    penalty on generating new binaries. It is recommended to not use this SDK at
    this time unless you are using an ATI 7xxx card that needs it.
    
    Q: Which AMD SDK is the best for cgminer?
    A: At the moment, versions 2.4 and 2.5 work the best for R5xxx and R6xxx GPUS.
    SDK 2.6 or 2.7 works best for R7xxx. SDK 2.8 is known to have many problems.
    If you are need to use the 2.6+ SDK or R7xxx or later, the phatk kernel will
    perform poorly, while the diablo or my custom modified poclbm kernel are
    optimised for it.
    
    Q: Which AMD driver is the best?
    A: Unfortunately AMD has a history of having quite a few releases with issues
    when it comes to mining, either in terms of breaking mining, increasing CPU
    usage or very low hashrates. Only experimentation can tell you for sure, but
    some good releases were 11.6, 11.12, 12.4 and 12.8
    
    Q: I have multiple SDKs installed, can I choose which one it uses?
    A: Run cgminer with the -n option and it will list all the platforms currently
    installed. Then you can tell cgminer which platform to use with --gpu-platform.
    
    Q: GUI version?
    A: No. The RPC interface makes it possible for someone else to write one
    though.
    
    Q: I'm having an issue. What debugging information should I provide?
    A: Start cgminer with your regular commands and add -D -T --verbose and provide
    the full startup output and a summary of your hardware, operating system, ATI
    driver version and ATI stream version.
    
    Q: cgminer reports no devices or only one device on startup on Linux although
    I have multiple devices and drivers+SDK installed properly?
    A: Try "export DISPLAY=:0" before running cgminer.
    
    Q: cgminer crashes immediately on startup.
    A: One of the common reasons for this is that you have mixed files on your
    machine for the driver or SDK. Windows has a nasty history of not cleanly
    uninstalling files so you may have to use third party tools like driversweeper
    to remove old versions. The other common reason for this is windows
    antivirus software is disabling one of the DLLs from working. If cgminer
    starts with the -T option but never starts without it, this is a sure fire
    sign you have this problem and will have to disable your antivirus or make
    exceptions.
    
    Q: Why don't you provide win64 builds?
    A: Win32 builds work everywhere and there is precisely zero advantage to a
    64 bit build on windows.
    
    Q: Is it faster to mine on windows or linux?
    A: It makes no difference. It comes down to choice of operating system for
    their various features. Linux offers much better long term stability and
    remote monitoring and security, while windows offers you overclocking tools
    that can achieve much more than cgminer can do on linux.
    
    Q: Cgminer cannot see any of my GPUs even though I have configured them all
    to be enabled and installed OpenCL (+/- Xorg is running and the DISPLAY
    variable is exported on linux)?
    A: Check the output of 'cgminer -n', it will list what OpenCL devices your
    installed SDK recognises. If it lists none, you have a problem with your
    version or installation of the SDK.
    
    Q: Cgminer is mining on the wrong GPU, I want it on the AMD but it's mining
    on my on board GPU?
    A: Make sure the AMD OpenCL SDK is installed, check the output of 'cgminer -n'
    and use the appropriate parameter with --gpu-platform.
    
    Q: I'm getting much lower hashrates than I should be for my GPU?
    A: Look at your driver/SDK combination and disable power saving options for
    your GPU. Specifically look to disable ULPS. Make sure not to set intensity
    above 11 for BTC mining.
    
    Q: Can I mine with AMD while running Nvidia or Intel GPUs at the same time?
    A: If you can install both drivers successfully (easier on windows) then
    yes, using the --gpu-platform option.
    
    Q: Can I mine with Nvidia or Intel GPUs?
    A: Yes but their hashrate is very poor and likely you'll be using much more
    energy than you'll be earning in coins.
    
    Q: Can I mine on Linux without running Xorg?
    A: With Nvidia you can, but with AMD you cannot.
    
    Q: I'm trying to mine litecoin but cgminer shows MH values instead of kH and
    submits no shares?
    A: Add the --scrypt parameter.
    
    Q: I can't get anywhere near enough hashrate for scrypt compared to other
    people?
    A: You may not have enough system RAM as this is also required.
    
    Q: My scrypt hashrate is high but the pool reports only a tiny proportion of
    my hashrate?
    A: You are generating garbage hashes due to your choice of settings. Your
    Work Utility (WU) value will confirm you are not generating garbage. You
    should be getting about .9WU per kHash. If not, then try decreasing your
    intensity, do not increase the number of gpu-threads, and consider adding
    system RAM to match your GPU ram.
    
    Q: Scrypt fails to initialise the kernel every time?
    A: Your parameters are too high. Don't add GPU threads, don't set intensity
    too high, decrease thread concurrency. See the SCRYPT-README for a lot more
    help.
    
    Q: My network gets slower and slower and then dies for a minute?
    A; Try the --net-delay option.
    
    Q: How do I tune for p2pool?
    A: p2pool has very rapid expiration of work and new blocks, it is suggested you
    decrease intensity by 1 from your optimal value, and decrease GPU threads to 1
    with -g 1. It is also recommended to use --failover-only since the work is
    effectively like a different block chain. If mining with a minirig, it is worth
    adding the --bfl-range option.
    
    Q: Are OpenCL kernels from other mining software useable in cgminer?
    A: No, the APIs are slightly different between the different software and they
    will not work.
    
    Q: I run PHP on windows to access the API with the example miner.php. Why does
    it fail when php is installed properly but I only get errors about Sockets not
    working in the logs?
    A: http://us.php.net/manual/en/sockets.installation.php
    
    Q: What is a PGA?
    A: At the moment, cgminer supports 4 FPGAs: BitForce, Icarus, ModMiner, and Ztex.
    They are Field-Programmable Gate Arrays that have been programmed to do Bitcoin
    mining. Since the acronym needs to be only 3 characters, the "Field-" part has
    been skipped.
    
    Q: How do I get my BFL/Icarus/Lancelot/Cairnsmore device to auto-recognise?
    A: On linux, if the /dev/ttyUSB* devices don't automatically appear, the only
    thing that needs to be done is to load the driver for them:
    BFL: sudo modprobe ftdi_sio vendor=0x0403 product=0x6014
    Icarus: sudo modprobe pl2303 vendor=0x067b product=0x230
    Lancelot: sudo modprobe ftdi_sio vendor=0x0403 product=0x6001
    Cairnsmore: sudo modprobe ftdi_sio product=0x8350 vendor=0x0403
    On windows you must install the pl2303 or ftdi driver required for the device
    pl2303: http://prolificusa.com/pl-2303hx-drivers/
    ftdi: http://www.ftdichip.com/Drivers/VCP.htm
    
    Q: On linux I can see the /dev/ttyUSB* devices for my Icarus FPGAs, but
    cgminer can't mine on them
    A: Make sure you have the required priviledges to access the /dev/ttyUSB* devices:
     sudo ls -las /dev/ttyUSB*
    will give output like:
     0 crw-rw---- 1 root dialout 188, 0 2012-09-11 13:49 /dev/ttyUSB0
    This means your account must have the group 'dialout' or root priviledges
    To permanently give your account the 'dialout' group:
     sudo usermod -G dialout -a `whoami`
    Then logout and back in again
    
    Q: Can I mine scrypt with FPGAs or ASICs?
    A: No.
    
    Q: What is stratum and how do I use it?
    A: Stratum is a protocol designed for pooled mining in such a way as to
    minimise the amount of network communications, yet scale to hardware of any
    speed. With versions of cgminer 2.8.0+, if a pool has stratum support, cgminer
    will automatically detect it and switch to the support as advertised if it can.
    Stratum uses direct TCP connections to the pool and thus it will NOT currently
    work through a http proxy but will work via a socks proxy if you need to use
    one. If you input the stratum port directly into your configuration, or use the
    special prefix "stratum+tcp://" instead of "http://", cgminer will ONLY try to
    use stratum protocol mining. The advantages of stratum to the miner are no
    delays in getting more work for the miner, less rejects across block changes,
    and far less network communications for the same amount of mining hashrate. If
    you do NOT wish cgminer to automatically switch to stratum protocol even if it
    is detected, add the --fix-protocol option.
    
    Q: Why don't the statistics add up: Accepted, Rejected, Stale, Hardware Errors,
    Diff1 Work, etc. when mining greater than 1 difficulty shares?
    A: As an example, if you look at 'Difficulty Accepted' in the RPC API, the number
    of difficulty shares accepted does not usually exactly equal the amount of work
    done to find them. If you are mining at 8 difficulty, then you would expect on
    average to find one 8 difficulty share, per 8 single difficulty shares found.
    However, the number is actually random and converges over time, it is an average,
    not an exact value, thus you may find more or less than the expected average.
    
    Q: Why do the scrypt diffs not match with the current difficulty target?
    A: The current scrypt block difficulty is expressed in terms of how many
    multiples of the BTC difficulty it currently is (eg 28) whereas the shares of
    "difficulty 1" are actually 65536 times smaller than the BTC ones. The diff
    expressed by cgminer is as multiples of difficulty 1 shares.
    
    ---
    
    This code is provided entirely free of charge by the programmer in his spare
    time so donations would be greatly appreciated. Please consider donating to the
    address below.
    
    Con Kolivas <kernel@kolivas.org>
    15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ