This is the official thread for support and development of cgminer, the combined GPU and FPGA bitcoin and litecoin miner written in c, cross platform for windows and linux, with overclocking, monitoring, fanspeed control and remote interface capabilities, completely overhauled based on the original code cpuminer.
This code is provided entirely free of charge by the programmer in his spare
time so donations would be greatly appreciated.
Help can also be obtained on IRC: irc.freenode.net #cgminer
READ THE README INCLUDED IN THE ARCHIVE BEFORE ASKING QUESTIONS WHICH CAN ALSO BE FOUND HERE:
http://ck.kolivas.org/apps/cgminer/README
Note that I can NOT provide personalised support via email or personal messages under normal circumstances so they will usually be ignored.
Apologies, but the demand is just far too great and I must prioritise my time.
All files available from here:
http://ck.kolivas.org/apps/cgminer
As a backup they can be downloaded here:
https://github.com/kanoi/cgminer-binaries
Debug builds are in http://ck.kolivas.org/apps/cgminer/debug/
.lrz files are compressed with lrzip http://lrzip.kolivas.org for much better compression and supports extreme encryption technology which is ideal for securing wallets.
LATEST RELEASE: 3.4.3
https://bitcointalk.org/index.php?topic=28402.msg3144100#msg3144100
Note that x86_64 binary is a 64 bit binary for UBUNTU 13.04.
Git tree:
https://github.com/ckolivas/cgminer
Latest git source tarball:
https://github.com/ckolivas/cgminer/tarball/master
Unofficial OSX binaries:
http://spaceman.ca/cgminer/
Features:
- Very low overhead free c code for Linux and windows with very low non-mining CPU and ram usage
- Stratum and GBT pooled mining protocol support
- Scaleable networking scheduler designed to scale to any size hashrate without networking delays yet minimise connection overhead
- Custom modified phatk, poclbm, diablo and diakgcn kernels
- BFI_INT patching
- VECTOR support
- Binary loading of kernels (fast startup)
- long poll support — will use longpoll from any pool if primary pool does not support it
- Self detection of new blocks with a mini-database for slow/failing longpoll scenarios, maximum work efficiency and minimum rejects.
- Heavily threaded code hands out work retrieval and work submission to separate threads to not hinder GPUs working
- Caching of submissions during transient network outages
- Preemptive fetching of work prior to completion of current work
- Local generation of more valid work (ntime rollover) whenever possible, as supported on a per-work item basis
- Prevention of stale work submission on new block
- Multi GPU support (all or discrete selection)
- Summarised and discrete device data statistics of requests, accepts, rejects, hw errors, efficiency and utility
- Watchdog thread to restart idle threads but not crash machine if they don’t respond
- Dynamic intensity that keeps desktop interactive under load and maximises throughput when deskop idle
- Summary displayed when quitting
- Supports multiple pools with multiple intelligent failover mechanisms
- Temporary disabling of misbehaving pools rejecting all shares
- On the fly menu based management of most settings
- Trickling of extra work to backup pools if primary pool is responding but slow
- On the fly enabling/disable/restarting of GPUs
- INTEGRATED GPU MONITORING, OVERCLOCKING AND FANCONTROL
- Auto fan and GPU clocking
- Dual GPU card support
- RPC +/- JSON interface for remote control
- Bitforce support — singles and minirig
- Icarus support
- Ztex support
- Modminer support
- Ability to cope with slow routers
- GPU device reordering by PCI Bus ID
- Submit-old support
- X-Reject-Reason support
- GCN (79×0) support
- Scrypt mining (litecoin)
- Variable difficulty support
- Restarts in the event of crashes
- Share difficulty reporting
- Target and block difficulty displays
- Block solve detection
- ASIC Avalon support
- Bitburner support
- Direct USB communications
- Device hotplug
- Heavily featured RPC API
- Multicast support
- Proxy support
- Lots of other stuff I can’t remember. See options.
Sample output:
Code:
cgminer version 3.3.4 — Started: [2013-08-21 20:51:35]
——————————————————————————–
(5s):133.2G (avg):133.7Gh/s | A:163264 R:460 HW:3069 WU:1871.0/m
ST: 2 SS: 5 NB: 11 LW: 165335 GF: 1 RF: 1
Connected to au.ozco.in diff 92 with stratum as user ckolivas.0
Block: 0015d36cd92d21d4… Diff:50.8M Started: [22:12:07] Best share: 4.92M
——————————————————————————–
[P]ool management [S]ettings [D]isplay options [Q]uit
BAJ 0: max 48C 3.45V | 8.407G/8.442Gh/s | A: 8849 R:184 HW: 152 WU: 118.3/m
BAS 0: max 80C 3.28V | 62.85G/62.75Gh/s | A:81501 R:184 HW:1592 WU: 880.6/m
BAS 1: max 72C 3.27V | 62.72G/62.62Gh/s | A:72914 R: 92 HW:1329 WU: 873.9/m
——————————————————————————–
[2013-08-21 22:15:29] Accepted 000dceb7 Diff 4.75K/92 BAS 0 pool 0
[2013-08-21 22:15:34] Accepted 01731d3c Diff 176/92 BAJ 0 pool 0
[2013-08-21 22:15:34] Accepted 00ab381c Diff 382/92 BAS 0 pool 0
[2013-08-21 22:15:36] Accepted 02af542e Diff 95/92 BAJ 0 pool 0
—
Pool menu:
Code:
0: Enabled Alive Priority 0:
http://www.guugll.eu:11327 User: FTCaddress
1: Enabled Alive Priority 1:
http://p2pool.org:9377 User: FTCaddress
2: Disabled Alive Priority 2:
http://p2pool.ru:9377 User: FTCaddress
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
GPU menu:
Code:
GPU 0: 426.7 / 427.9 Mh/s | A:199 R:0 HW:0 U:6.09/m
72.5 C F: 50% 4490 RPM) E: 950 MHz M: 825 Mhz V: 1.175V A: 99% P: 20%
Last initialised: [2011-09-09 12:11:33]
Thread 0: 227.4 Mh/s Enabled ALIVE
Thread 4: 226.1 Mh/s Enabled ALIVE
GPU 1: 426.2 / 427.9 Mh/s | A:186 R:1 HW:0 U:5.69/m
72.5 C F: 67% 4011 RPM) E: 950 MHz M: 825 Mhz V: 1.175V A: 99% P: 20%
Last initialised: [2011-09-09 12:11:33]
Thread 1: 213.6 Mh/s Enabled ALIVE
Thread 5: 214.2 Mh/s Enabled ALIVE
GPU 2: 430.9 / 428.0 Mh/s | A:178 R:5 HW:0 U:5.44/m
73.5 C F: 47% 4247 RPM) E: 950 MHz M: 825 Mhz V: 1.175V A: 99% P: 20%
Last initialised: [2011-09-09 12:11:33]
Thread 2: 212.8 Mh/s Enabled ALIVE
Thread 6: 188.3 Mh/s Enabled ALIVE
GPU 3: 430.7 / 427.9 Mh/s | A:175 R:2 HW:0 U:5.35/m
73.5 C F: 56% 3414 RPM) E: 950 MHz M: 825 Mhz V: 1.175V A: 99% P: 20%
Last initialised: [2011-09-09 12:11:33]
Thread 3: 214.8 Mh/s Enabled ALIVE
Thread 7: 215.1 Mh/s Enabled ALIVE
Change settings menu:
Code:
Select GPU to change settings on: 0
Temp: 72.0 C
Fan Speed: 50% (4489 RPM)
Engine Clock: 950 MHz
Memory Clock: 825 Mhz
Vddc: 1.175 V
Activity: 99%
Powertune: 20%
Fan autotune is enabled (0-85)
GPU engine clock autotune is enabled (880-950)
Change [A]utomatic [E]ngine [F]an [M]emory [V]oltage [P]owertune
Or press any other key to continue
Settings menu:
Code:
[Q]ueue: 1
[S]cantime: 60
[E]xpiry: 120
[W]rite config file
[C]gminer restart
Display menu:
Code:
[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
[Z]ero statistics
On exiting:
Code:
Summary of runtime statistics:
Started at [2011-07-19 14:40:09]
Runtime: 2 hrs : 31 mins : 18 secs
Average hashrate: 1680.1 Megahash/s
Queued work requests: 3317
Share submissions: 3489
Accepted shares: 3489
Rejected shares: 0
Reject ratio: 0.0
Hardware errors: 0
Efficiency (accepted / queued): 105%
Utility (accepted shares / min): 23.06/min
Discarded work due to new blocks: 0
Stale submissions discarded due to new blocks: 9
Unable to get work from server occasions: 16
Work items generated locally: 330
Submitting work remotely delay occasions: 33
New blocks detected on network: 10
Pool: http://www.guugll.eu:11327
Queued work requests: 3253
Share submissions: 3426
Accepted shares: 3426
Rejected shares: 0
Reject ratio: 0.0
Efficiency (accepted / queued): 105%
Discarded work due to new blocks: 0
Stale submissions discarded due to new blocks: 9
Unable to get work from server occasions: 15
Submitting work remotely delay occasions: 33
Pool: http://www.guugll.eu:11327
Queued work requests: 64
Share submissions: 63
Accepted shares: 63
Rejected shares: 0
Reject ratio: 0.0
Efficiency (accepted / queued): 98%
Discarded work due to new blocks: 0
Stale submissions discarded due to new blocks: 0
Unable to get work from server occasions: 1
Submitting work remotely delay occasions: 0
Summary of per device statistics:
GPU 0: [419.9 Mh/s] [Q:913 A:901 R:0 HW:0 E:99% U:5.96/m]
GPU 1: [420.1 Mh/s] [Q:912 A:865 R:0 HW:0 E:95% U:5.72/m]
GPU 2: [420.5 Mh/s] [Q:908 A:865 R:0 HW:0 E:95% U:5.72/m]
GPU 3: [419.6 Mh/s] [Q:910 A:858 R:0 HW:0 E:94% U:5.68/m]
—
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
–device|-d <arg> Select device to use, one value, range and/or comma separated (e.g. 0-2,4) default: all
–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)
—lowmem Minimise caching of shares for low memory applications
-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-restart Do not attempt to restart GPUs that hang
–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
–retries|-r <arg> Number of times to retry before giving up, if JSON-RPC call fails (-1 means never) (default: -1)
–retry-pause|-R <arg> Number of seconds to pause, between retries (default: 5)
–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)
–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
–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
–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.
Cgminer will automatically find all of your Avalon ASIC, BFL ASIC, BitForce
FPGAs, Icarus bitstream FPGAs, ModMiner FPGAs, or Ztex FPGAs
ASIC and FPGA mining boards (Avalon, BFL ASIC, BitForce, Icarus, ModMiner, Ztex)
only options:
–avalon-options <arg> Set avalon options baud:miners:asic:timeout:freq
–avalon-temp <arg> Set avalon target temperature (default: 45)
–bfl-range Use nonce range on bitforce devices if supported
–icarus-options <arg> Set specific FPGA board configurations — one set of values for all or comma separated
–icarus-timing <arg> Set how the Icarus timing is calculated — one setting/value for all or comma separated
–usb <arg> USB device selection (See below)
–usb-dump (See FPGA-README)
For other ASIC details see the ASIC-README
For other FPGA details see the FPGA-README
—
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 FTC pool, regular desktop:
cgminer -o http://www.guugll.eu:11327 -u username -p password
Single FTC pool, dedicated miner:
cgminer -o http://www.guugll.eu:11327 -u username -p password -I 9
Single FTC pool, first card regular desktop, 3 other dedicated cards:
cgminer -o http://www.guugll.eu:11327 -u username -p password -I d,9,9,9
Multiple FTC pool, dedicated miner:
cgminer -o http://www.guugll.eu:11327 -u pool1username -p pool1password -o http://p2pool.org:9377 -u pool2usernmae -p pool2password -I 9
Add overclocking settings, GPU and fan control for all cards:
cgminer -o http://www.guugll.eu:11327 -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://www.guugll.eu:11327 -u username -p password -I 9 –auto-fan –auto-gpu –gpu-engine 750-950,945,700-930,960 –gpu-memclock 300
READ WARNINGS AND DOCUMENTATION BELOW ABOUT OVERCLOCKING
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
—
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
[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
[R]etries: -1
[P]ause: 5
[W]rite config file
D gives you:
Toggle: [D]ebug [N]ormal [ S]ilent [V]erbose [R]PC debug
[L]og interval [C]lear
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
—
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 | 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:
TQ: 1 ST: 1 SS: 0 DW: 0 NB: 1 LW: 8 GF: 1 RF: 1
TQ is Total Queued work items.
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)
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.
—
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.
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 69×0+ 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.
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. Note that older cards may
not work with the newer drivers.
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: Can I mine with cgminer on a MAC?
A: cgminer will compile on OSX, but the performance of GPU mining is
compromised due to the opencl implementation on OSX, there is no temperature
or fanspeed monitoring, and the cooling design of most MACs, despite having
powerful GPUs, will usually not cope with constant usage leading to a high
risk of thermal damage. It is highly recommended not to mine on a MAC unless
it is to a USB device.
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 both Nvidia and AMD GPUs at the same time?
A: No, you must run one instance of cgminer with the –gpu-platform option for
each.
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. You may also be using a bad combination
of driver and/or SDK.
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: Cgminer stops mining (or my GPUs go DEAD) and I can’t close it?
A: Once the driver has crashed, there is no way for cgminer to close cleanly.
You will have to kill it, and depending on how corrupted your driver state
has gotten, you may even need to reboot. Windows is known to reset drivers
when they fail and cgminer will be stuck trying to use the old driver instance.
Q: I can’t get any monitoring of temperatures or fanspeed with cgminer when
I start it remotely?
A: With linux, make sure to export the DISPLAY variable. On windows, you
cannot access these monitoring values via RDP. This should work with tightVNC
or teamviewer though.
Q: I change my GPU engine/memory/voltage and cgminer reports back no change?
A: Cgminer asks the GPU using the ATI Display Library to change settings, but
the driver and hardware are free to do what it wants with that query, including
ignoring it. Some GPUs are locked with one or more of those properties as well.
Q: I have multiple GPUs and although many devices show up, it appears to be
working only on one GPU splitting it up.
A: Your driver setup is failing to properly use the accessory GPUs. Your
driver may be configured wrong or you have a driver version that needs a dummy
plug on all the GPUs that aren’t connected to a monitor.
Q: Should I use crossfire/SLI?
A: It does not benefit mining at all and depending on the GPU may actually
worsen performance.
Q: I have some random GPU performance related problem not addressed above.
A: Seriously, it’s the driver and/or SDK. Uninstall them and start again,
noting there is no clean way to uninstall them so you have to use extra tools
or do it manually.
Q: Do I need to recompile after updating my driver/SDK?
A: No. The software is unchanged regardless of which driver/SDK/ADL_SDK version
you are running. However if you change SDKs you should delete any generated
.bin files for them to be recreated with the new SDK.
Q: I switch users on windows and my mining stops working?
A: That’s correct, it does. It’s a permissions issue that there is no known
fix for due to monitoring of GPU fanspeeds and temperatures. If you disable
the monitoring with –no-adl it should switch okay.
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=0×0403 product=0×6014
Icarus: sudo modprobe pl2303 vendor=0x067b product=0×230
Lancelot: sudo modprobe ftdi_sio vendor=0×0403 product=0×6001
Cairnsmore: sudo modprobe ftdi_sio product=0×8350 vendor=0×0403
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.
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
source: https://bitcointalk.org/index.php?topic=28402.0
Guugll Search
http://www.guugll.eu/cgminer-asic-fpga-gpu/
