This README contains extended details about FPGA mining with cgminer
Bitforce
--bfl-range Use nonce range on bitforce devices if supported
This option is only for bitforce devices. Earlier devices such as the single
did not have any way of doing small amounts of work which meant that a lot of
work could be lost across block changes. Some of the "minirigs" have support
for doing this, so less work is lost across a longpoll. However, it comes at
a cost of 1% in overall hashrate so this feature is disabled by default. It
is only recommended you enable this if you are mining with a minirig on
p2pool.
Icarus
@ -12,45 +24,45 @@ There is a hidden option in cgminer when Icarus support is compiled in:
@@ -12,45 +24,45 @@ There is a hidden option in cgminer when Icarus support is compiled in:
long Re-calculate the hash time continuously
value[=N] Specify the hash time in nanoseconds (e.g. 2.6316) and abort time (e.g. 2.6316=80)
Icarus timing is required for devices that do not exactly match a default Icarus Rev3 in
processing speed
If you have an Icarus Rev3 you should not normally need to use --icarus-timing since the
default values will maximise the MH/s and display it correctly
Icarus timing is used to determine the number of hashes that have been checked when it aborts
a nonce range (including on a LongPoll)
It is also used to determine the elapsed time when it should abort a nonce range to avoid
letting the Icarus go idle, but also to safely maximise that time
'short' or 'long' mode should only be used on a computer that has enough CPU available to run
cgminer without any CPU delays (an active desktop or swapping computer would not be stable enough)
Any CPU delays while calculating the hash time will affect the result
'short' mode only requires the computer to be stable until it has completed ~315 difficulty 1 shares
'long' mode requires it to always be stable to ensure accuracy, however, over time it continually
corrects itself
When in 'short' or 'long' mode, it will report the hash time value each time it is re-calculated
In 'short' or 'long' mode, the scan abort time starts at 5 seconds and uses the default 2.6316ns
scan hash time, for the first 5 nonce's or one minute (whichever is longer)
In 'default' or 'value' mode the 'constants' are calculated once at the start, based on the default
value or the value specified
The optional additional =N specifies to set the default abort at N 1/10ths of a second, not the
calculated value, which is 112 for 2.6316ns
To determine the hash time value for a non Icarus Rev3 device or an Icarus Rev3 with a different
bitstream to the default one, use 'long' mode and give it at least a few hundred shares, or use
'short' mode and take note of the final hash time value (Hs) calculated
You can also use the RPC API 'stats' command to see the current hash time (Hs) at any time
The Icarus code currently only works with a dual FPGA device that supports the same commands as
Icarus Rev3 requires and also is less than ~840MH/s and greater than 2MH/s
If a dual FPGA device does hash faster than ~840MH/s it should work correctly if you supply the
correct hash time nanoseconds value
The timing code itself will affect the Icarus performance since it increases the delay after
work is completed or aborted until it starts again
The increase is, however, extremely small and the actual increase is reported with the
RPC API 'stats' command (a very slow CPU will make it more noticeable)
Using the 'short' mode will remove this delay after 'short' mode completes
The delay doesn't affect the calculation of the correct hash time
Icarus timing is required for devices that do not exactly match a default Icarus Rev3 in
processing speed
If you have an Icarus Rev3 you should not normally need to use --icarus-timing since the
default values will maximise the MH/s and display it correctly
Icarus timing is used to determine the number of hashes that have been checked when it aborts
a nonce range (including on a LongPoll)
It is also used to determine the elapsed time when it should abort a nonce range to avoid
letting the Icarus go idle, but also to safely maximise that time
'short' or 'long' mode should only be used on a computer that has enough CPU available to run
cgminer without any CPU delays (an active desktop or swapping computer would not be stable enough)
Any CPU delays while calculating the hash time will affect the result
'short' mode only requires the computer to be stable until it has completed ~315 difficulty 1 shares
'long' mode requires it to always be stable to ensure accuracy, however, over time it continually
corrects itself
When in 'short' or 'long' mode, it will report the hash time value each time it is re-calculated
In 'short' or 'long' mode, the scan abort time starts at 5 seconds and uses the default 2.6316ns
scan hash time, for the first 5 nonce's or one minute (whichever is longer)
In 'default' or 'value' mode the 'constants' are calculated once at the start, based on the default
value or the value specified
The optional additional =N specifies to set the default abort at N 1/10ths of a second, not the
calculated value, which is 112 for 2.6316ns
To determine the hash time value for a non Icarus Rev3 device or an Icarus Rev3 with a different
bitstream to the default one, use 'long' mode and give it at least a few hundred shares, or use
'short' mode and take note of the final hash time value (Hs) calculated
You can also use the RPC API 'stats' command to see the current hash time (Hs) at any time
The Icarus code currently only works with a dual FPGA device that supports the same commands as
Icarus Rev3 requires and also is less than ~840MH/s and greater than 2MH/s
If a dual FPGA device does hash faster than ~840MH/s it should work correctly if you supply the
correct hash time nanoseconds value
The timing code itself will affect the Icarus performance since it increases the delay after
work is completed or aborted until it starts again
The increase is, however, extremely small and the actual increase is reported with the
RPC API 'stats' command (a very slow CPU will make it more noticeable)
Using the 'short' mode will remove this delay after 'short' mode completes
The delay doesn't affect the calculation of the correct hash time
--scan-serial|-S <arg> Serial port to probe for FPGA mining device
This option is only for BitForce, Icarus, and/or ModMiner FPGAs
This option is only for BitForce, Icarus, and/or ModMiner 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.
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)
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"
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"
For other FPGA details see the FPGA-README
@ -795,7 +795,9 @@ A; Try the --net-delay option.
@@ -795,7 +795,9 @@ 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.
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
@ -812,6 +814,13 @@ They are Field-Programmable Gate Arrays that have been programmed to do Bitcoin
@@ -812,6 +814,13 @@ 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 device to auto-recognise?
A: They are only automatically recognised on linux, and no option needs to be
passed to them. The only thing that needs to be done is to load the driver for
Con Kolivas
13 years ago