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ASIC and FPGA miner in c for bitcoin
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This is a multi-threaded multi-pool GPU, FPGA and CPU 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 <>



Support thread:

IRC Channel:


License: GPLv3.  See COPYING for details.


	curl dev library

	curses dev library
	(libncurses5-dev or libpdcurses on WIN32)


	(jansson is included in-tree and not necessary)

	yasm 1.0.1+
	(yasm is optional, gives assembly routines for CPU mining)

	(This sdk is mandatory for GPU mining)

	(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:
	--enable-cpumining      Build with cpu mining support(default disabled)
	--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:

This will give you a file with a name like AMD-APP-SDK-v2.4-lnx64.tgz


sudo su
cd /opt
tar xf /path/to/AMD-APP-SDK-v2.4-lnx64.tgz
cd /
tar xf /opt/AMD-APP-SDK-v2.4-lnx64/icd-registration.tgz
ln -s /opt/AMD-APP-SDK-v2.4-lnx64/include/CL /usr/include
ln -s /opt/AMD-APP-SDK-v2.4-lnx64/lib/x86_64/* /usr/lib/

If you are on 32 bit, x86_64 in the 2nd last line should be x86

	To actually build:

	./	# 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
	If it finds the opencl files it will inform you with
	"OpenCL: FOUND. GPU mining support enabled."

Basic WIN32 build instructions (LIKELY OUTDATED INFO. requires mingw32):
	./	# only needed if building from git repo
	rm -f mingw32-config.cache
	MINGW32_CFLAGS="-O2 -Wall -msse2" mingw32-configure
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 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
--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
--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)
--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-pool-disable   Do not automatically disable pools that continually reject shares
--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
--thread-concurrency <arg> Set GPU thread concurrency for scrypt mining, comma separated

See SCRYPT-README for more information regarding litecoin mining.

FPGA mining boards(BitForce, Icarus, ModMiner, Ztex) only options:

cgminer will automatically find your ModMiner or Ztex FPGAs

--scan-serial|-S <arg> Serial port to probe for FPGA mining device

This option is only for BitForce and/or Icarus FPGAs

By default, cgminer will scan for autodetected FPGAs 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 FPGA 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 "bitforce:\\.\COM5"
or using the short name: "ica:/dev/ttyUSB0" or "bfl:\\.\COM5"

For other FPGA details see the FPGA-README

CPU only options (deprecated, not included in binaries!):

--algo|-a <arg>     Specify sha256 implementation for CPU mining:
        auto            Benchmark at startup and pick fastest algorithm
        c               Linux kernel sha256, implemented in C
        4way            tcatm's 4-way SSE2 implementation
        via             VIA padlock implementation
        cryptopp        Crypto++ C/C++ implementation
        sse2_64         SSE2 64 bit implementation for x86_64 machines
        sse4_64         SSE4.1 64 bit implementation for x86_64 machines (default: sse2_64)
--cpu-threads|-t <arg> Number of miner CPU threads (default: 4)
--enable-cpu|-C     Enable CPU mining with other mining (default: no CPU mining if other devices exist)



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


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



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)
[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] [Q:212  A:77  R:33  HW:0  E:36%  U: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,

The output line shows the following:
(5s):1713.6 (avg):1707.8 Mh/s | Q:301  A:729  R:8  HW:0  E:242%  U:22.53/m

Each column is as follows:
5s:  A 5 second exponentially decaying average hash rate
avg: An all time average hash rate
Q:   The number of requested (Queued) work items from the pools
A:   The number of Accepted shares
R:   The number of Rejected shares
HW:  The number of HardWare errors
E:   The Efficiency defined as number of shares returned / work item
U:   The Utility defined as the number of shares / minute

 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  DW: 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)
DW is Discarded Work items (work from block no longer valid to work on)
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. Higher values are
there to cope with future improvements in hardware.

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 submitted since starting cgminer
this time.


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:

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.

This strategy only moves from one pool to the next when the current one falls
idle and makes no attempt to move otherwise.

This strategy moves at user-defined intervals from one active pool to the next,
skipping pools that are idle.

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.

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.


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)
For example (this is wrapped, but it's all on one line for real):



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,
--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.

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 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 (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 75,85
Sets card 0 overheat threshold to 75 degrees and card 1 to 85.

--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:
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 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.

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.

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.



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.
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



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.

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

Q: Work keeps going to my backup pool even though my primary pool hasn't
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

Q: Why is my efficiency above/below 100%?
A: Efficiency simply means how many shares you return for the amount of work
you request. It does not correlate with efficient use of your hardware, and is
a measure of a combination of hardware speed, block luck, pool design and other

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 unless someone
steps up to help maintain it. No binary builds supporting CPU mining will be
released but CPU mining can be built into cgminer when it is compiled.

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 ATI SDK is the best for cgminer?
A: At the moment, versions 2.4 and 2.5 work the best. If you are forced to use
the 2.6 SDK, the phatk kernel will perform poorly, while the diablo or my
custom modified poclbm kernel are optimised for it.

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

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: 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 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?

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

Q: On linux I can see the /dev/ttyUSB* devices for my ICA/BFL FPGA, 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: 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.


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 <>
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