bfgminer/README

BFGMiner:
St. Barbara's Faithfully Glorified Mining Initiative Naturally Exceeding Rivals
or Basically a Freaking Good Miner

This is a multi-threaded multi-pool ASIC, FPGA, GPU and CPU miner with dynamic
clocking, monitoring, and fanspeed support for bitcoin. 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.

Luke-Jr <luke-jr+bfgminer@utopios.org>
1QATWksNFGeUJCWBrN4g6hGM178Lovm7Wh

DOWNLOADS:

http://luke.dashjr.org/programs/bitcoin/files/bfgminer

GIT TREE:

https://github.com/luke-jr/bfgminer

Bug reports:

https://github.com/luke-jr/bfgminer/issues

IRC Channel:

irc://irc.freenode.net/eligius

License: GPLv3.  See COPYING for details.

SEE ALSO README.FPGA, README.GPU, README.RPC, AND README.scrypt FOR MORE
INFORMATION ON EACH.

---

EXECUTIVE SUMMARY ON USAGE:

After saving configuration from the menu, you do not need to give BFGMiner 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:

bfgminer -o http://pool:port -u username -p password

Multiple pools:

bfgminer -o http://pool1:port -u pool1username -p pool1password -o http://pool2:port -u pool2usernmae -p pool2password

Single pool with a standard http proxy, regular desktop:

bfgminer -o http://pool:port -x http://proxy:port -u username -p password

Single pool with a socks5 proxy, regular desktop:

bfgminer -o http://pool:port -x socks5://proxy:port -u username -p password

The list of proxy types are:
 http:    standard http 1.1 proxy
 socks4:  socks4 proxy
 socks5:  socks5 proxy
 socks4a: socks4a proxy
 socks5h: socks5 proxy using a hostname

Proxy support requires cURL version 7.21.7 or newer.

If you specify the --socks-proxy option to BFGMiner, it will only be applied to
all pools that don't specify their own proxy setting like above

---
BUILDING BFGMINER

Dependencies:
	autoconf             http://www.gnu.org/software/autoconf/
	automake             http://www.gnu.org/software/automake/
	libtool              http://www.gnu.org/software/libtool/
	pkg-config           http://www.freedesktop.org/wiki/Software/pkg-config
	...or pkgconf        https://github.com/pkgconf/pkgconf

	libcurl4-gnutls-dev  http://curl.haxx.se/libcurl/

	libjansson-dev 2.0+  http://www.digip.org/jansson/

Optional Dependencies:
	Text-User-Interface (TUI): curses dev library; any one of:
	  libncurses5-dev    http://www.gnu.org/software/ncurses/ (Linux and Mac)
	  libncursesw5-dev       ^ same
	  libpdcurses        http://pdcurses.sourceforge.net/ (Linux/Mac/Windows)

	Multiple ASIC/FPGA autodetection: any one of:
	  sysfs              (builtin to most Linux kernels, just mount on /sys)
	  libudev-dev        http://www.freedesktop.org/software/systemd/libudev/

	X6500 and ZTEX FPGA boards:
	  libusb-1.0-0-dev   http://www.libusb.org/

	ATi/AMD video card GPU mining:
	  AMD APP SDK        http://developer.amd.com/tools/heterogeneous-computing/amd-accelerated-parallel-processing-app-sdk/

	CPU mining optimized assembly algorithms:
	  yasm 1.0.1+        http://yasm.tortall.net/


BFGMiner specific configuration options:
	--enable-avalon         Compile support for Avalon (default disabled)
	--enable-cpumining      Build with cpu mining support(default disabled)
	--disable-opencl        Build without support for OpenCL (default enabled)
	--disable-adl           Build without ADL monitoring (default enabled)
	--disable-bitforce      Compile support for BitForce (default enabled)
	--disable-icarus        Compile support for Icarus (default enabled)
	--disable-modminer      Compile support for ModMiner (default enabled)
	--disable-x6500         Compile support for X6500 (default enabled)
	--disable-ztex          Compile support for ZTEX (default if libusb)
	--enable-scrypt         Compile support for scrypt mining (default disabled)
	--without-curses        Compile support for curses TUI (default enabled)
	--without-libudev       Autodetect FPGAs using libudev (default enabled)

Basic *nix build instructions:

./autogen.sh    # only needed if building from git repo
./configure
make

No installation is necessary. You may run BFGMiner from the build directory
directly.

On Mac OS X, you can use Homebrew to install the dependency libraries. When you
are ready to build BFGMiner, you may need to point the configure script at one
or more pkg-config paths. For example:
	./configure PKG_CONFIG_PATH=/usr/local/opt/curl/lib/pkgconfig:/usr/local/opt/jansson/lib/pkgconfig

Native WIN32 build instructions: see windows-build.txt

If you build BFGMiner from source, it is recommended that you run it from the
build directory. On *nix, you will usually need to prepend your command with a
path like this (if you are in the bfgminer directory already): ./bfgminer

---

Usage instructions:  Run "bfgminer --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: BFGMiner version)
--api-groups        API one letter groups G:cmd:cmd[,P:cmd:*...]
                    See README.RPC 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)
--balance           Change multipool strategy from failover to even share balance
--benchmark         Run BFGMiner in benchmark mode - produces no shares
--coinbase-addr <arg> Set coinbase payout address for solo mining
--coinbase-sig <arg> Set coinbase signature when possible
--compact           Use compact display without per device statistics
--debug|-D          Enable debug output
--debuglog          Enable debug logging
--device|-d <arg>   Select device to use, (Use repeat -d for multiple devices, default: all)
--disable-rejecting Automatically disable pools that continually reject shares
--expiry|-E <arg>   Upper bound on how many seconds after getting work we consider a share from it stale (w/o longpoll active) (default: 120)
--expiry-lp <arg>   Upper bound on how many seconds after getting work we consider a share from it stale (with longpoll active) (default: 3600)
--failover-only     Don't leak work to backup pools when primary pool is lagging
--force-dev-init    Always initialize devices when possible (such as bitstream uploads to some FPGAs)
--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-gbt            Disable getblocktemplate support
--no-getwork        Disable getwork support
--no-longpoll       Disable X-Long-Polling support
--no-restart        Do not attempt to restart devices that hang
--no-stratum        Disable Stratum detection
--no-submit-stale   Don't submit shares if they are detected as stale
--no-opencl-binaries Don't attempt to use or save OpenCL kernel binaries
--pass|-p <arg>     Password for bitcoin JSON-RPC server
--per-device-stats  Force verbose mode and output per-device statistics
--pool-proxy|-x     Proxy URI to use for connecting to just the previous-defined pool
--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
--request-diff <arg> Request a specific difficulty from pools (default: 1.0)
--retries <arg>     Number of times to retry failed submissions before giving up (-1 means never) (default: -1)
--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 (non-bitcoin)
--sharelog <arg>    Append share log to file
--shares <arg>      Quit after mining N shares (default: unlimited)
--show-processors   Show per processor statistics in summary
--skip-security-checks <arg> Skip security checks sometimes to save bandwidth; only check 1/<arg>th of the time (default: never skip)
--socks-proxy <arg> Set socks4 proxy (host:port) for all pools without a proxy specified
--submit-threads    Minimum number of concurrent share submissions (default: 64)
--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)
--temp-hysteresis <arg> Set how much the temperature can fluctuate outside limits when automanaging speeds (default: 3)
--temp-target <arg> Target temperature when automatically managing fan and clock speeds
--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-platform <arg> Select OpenCL platform ID to use for GPU mining
--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-adl            Disable the ATI display library used for monitoring and setting GPU parameters
--temp-overheat <arg> Overheat temperature when automatically managing fan and GPU speeds (default: 85)
--vectors|-v <arg>  Override detected optimal vector (1, 2 or 4) - one value or comma separated list
--worksize|-w <arg> Override detected optimal worksize - one value or comma separated list


scrypt only options:

--lookup-gap <arg>  Set GPU lookup gap for scrypt mining, comma separated
--shaders <arg>     GPU shaders per card for tuning scrypt, comma separated
--thread-concurrency <arg> Set GPU thread concurrency for scrypt mining, comma separated

See README.scrypt for more information regarding (non-bitcoin) scrypt mining.


ASIC/FPGA mining boards (BitForce, Icarus, ModMiner, X6500, ZTEX) only options:

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

To use ASICs or FPGAs, you will need to be sure the user BFGMiner is running as
has appropriate permissions. This varies by operating system.
On Gentoo: sudo usermod <username> -a -G uucp
On Ubuntu: sudo usermod <username> -a -G dialout
Note that on GNU/Linux systems, you will usually need to login again before
group changes take effect.

By default, BFGMiner will scan for autodetected devices unless at least one -S
is specified for that driver. If you specify -S and still want BFGMiner to scan,
you must also use "-S auto". If you want to prevent BFGMiner 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. If you want to scan all serial ports, you
can use "-S all"; note that this may write data to non-mining devices which may
then behave in unexpected ways!

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 device)

The official supplied binaries are compiled with support for all ASICs/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"

Some FPGAs do not have non-volatile storage for their bitstreams and must be
programmed every power cycle, including first use. To use these devices, you
must download the BFGMiner source archive (bfgminer-x.y.z.zip) and copy the
"bitstreams" directory into your BFGMiner application directory.

For other FPGA details see the README.FPGA


CPU only options (not included in binaries):

--algo|-a <arg>     Specify sha256 implementation for CPU mining:
        fastauto*       Quick benchmark at startup to pick a working algorithm
        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
        cryptopp_asm32  Crypto++ 32-bit assembler implementation
        sse2_32         SSE2 32 bit implementation for i386 machines
        sse2_64         SSE2 64 bit implementation for x86_64 machines
        sse4_64         SSE4.1 64 bit implementation for x86_64 machines
        altivec_4way    Altivec implementation for PowerPC G4 and G5 machines
--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)


---

WHILE RUNNING:

The following options are available while running with a single keypress:

[P]ool management [G]PU management [S]ettings [D]isplay options [Q]uit

P gives you:

Current pool management strategy: Failover
[F]ailover only disabled
[A]dd pool [R]emove pool [D]isable pool [E]nable pool
[C]hange management strategy [S]witch pool [I]nformation


S gives you:

[L]ongpoll: On
[Q]ueue: 1
[S]cantime: 60
[E]xpiry: 120
[R]etries: -1
[W]rite config file
[B]FGMiner restart


D gives you:

[N]ormal [C]lear [S]ilent mode (disable all output)
[D]ebug:off
[P]er-device:off
[Q]uiet:off
[V]erbose:off
[R]PC debug:off
[W]orkTime details:off
co[M]pact: off
[L]og interval:5


Q quits the application.


G gives you something like:

GPU 0: [124.2 / 191.3 Mh/s] [A:77  R:33+0( 42%)  HW:0]
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:

 [2013-02-13 00:26:30] Accepted 1758e8df BFL 0  pool 0 Diff 10/1
 [2013-02-13 00:26:32] Accepted 1d9a2199 MMQ 0a pool 0 Diff 8/1
 [2013-02-13 00:26:33] Accepted b1304924 ZTX 0  pool 0 Diff 1/1
 [2013-02-13 00:26:33] Accepted c3ad22f4 XBS 0b pool 0 Diff 1/1

The 8 byte hex value are the 2nd set of 32 bits from the share 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 threads
dedicated to this program,
	https://bitcointalk.org/?topic=78192
	https://bitcointalk.org/?topic=168174

The output line shows the following:
 5s:1713.6 avg:1707.8 u:1710.2 Mh/s | A:729 R:8+0(.01%) HW:0

Each column is as follows:
5s:  A 5 second exponentially decaying average hash rate
avg: An all time average hash rate
u:   An all time average hash rate based on actual accepted shares
A:   The number of Accepted shares
R:   The number of Rejected shares, stale shares discarded (never submitted),
     and the percentage these are of total found.
HW:  The number of HardWare errors

 GPU 1: 73.5C 2551RPM | 427.3/443.0/442.1Mh/s | A:8 R:0+0(none) 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
An all time average hash rate based on actual accepted shares
The number of accepted shares
The number of rejected shares (and percentage of total submitted)
The number of hardware erorrs
The utility defines as the number of shares / minute

The BFGMiner status line shows:
 ST: 1  GF: 1  NB: 1  AS: 0  RF: 1  E: 2.42  U:22.53/m  BS:2.71k

ST is STaged work items (ready to use).
GF is Getwork Fail Occasions (server slow to provide work)
NB is New Blocks detected on the network
AS is Active Submissions (shares in the process of submitting)
RF is Remote Fail occasions (server slow to accept work)
E  is Efficiency defined as number of shares accepted (multiplied by their
          difficulty) per 2 KB of bandwidth
U  is Utility defined as the number of shares / minute
BS is the all time Best Share difficulty you've found

The block display shows:
Block: ...1b89f8d3 #217364  Diff:7.67M (54.93Th/s)  Started: [17:17:22]

This shows a short stretch of the current block, the next block's height and
difficulty (including the network hashrate that difficulty represents), and when
the search for the new block started.


---
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.


---
SOLO MINING

BFGMiner supports solo mining with any GBT-compatible bitcoin node (such as
bitcoind). To use this mode, you need to specify the URL of your bitcoind node
using the usual pool options (--url, --userpass, etc), and the --coinbase-addr
option to specify the Bitcoin address you wish to receive the block rewards
mined. If you are solo mining with more than one instance of BFGMiner (or any
other software) per payout address, you must also specify data using the
--coinbase-sig option to ensure each miner is working on unique work. Note
that this data will be publicly seen if your miner finds a block using any
GBT-enabled pool, even when not solo mining (such as failover). If your
bitcoin node does not support longpolling (for example, bitcoind 0.7.x), you
should consider setting up a failover pool to provide you with block
notifications.

Example solo mining usage:

bfgminer -o http://localhost:8332 -u username -p password \
    --coinbase-addr 1QATWksNFGeUJCWBrN4g6hGM178Lovm7Wh \
    --coinbase-sig "rig1: This is Joe's block!"


---
LOGGING

BFGMiner 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:
./bfgminer -o xxx -u yyy -p zzz
if you use
./bfgminer -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 its 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 BFGMiner 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:
./bfgminer --sharelog 50 -o xxx -u yyy -p zzz 50>share.log
./bfgminer --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

---

RPC API

For RPC API details see the README.RPC file

---

FAQ

Q: Why can't BFGMiner find lib<something> even after I installed it from source
code?
A: On UNIX-like operating systems, you often need to run some command to reload
its library caches such as "ldconfig" or similar. A couple of systems (such as
Fedora) ship with /usr/local/lib missing from their library search path. In
this case, you can usually add it like this:
    echo /usr/local/lib >/etc/ld.so.conf.d/local.conf
Please note that if your libraries installed into lib64 instead of lib, you
should use that in the ld.so config file above instead.

Q: BFGMiner 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, BFGMiner 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 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: 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: Work keeps going to my backup pool even though my primary pool hasn't
failed?
A: BFGMiner 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: BFGMiner is being packaged with other trojan scripts and some antivirus
software is falsely accusing bfgminer.exe as being the actual virus, rather
than whatever it is being packaged with. If you installed BFGMiner 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 BFGMiner
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: Why is my efficiency above/below 1.00?
A: Efficiency simply means how many shares you return for the amount of
bandwidth used. 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 factors.

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 for GPUs.

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 BFGMiner when it is compiled.

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 BFGMiner 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: Can I mine with BFGMiner on a Mac?
A: BFGMiner will compile on OS X, but the performance of GPU mining is
compromised due to the OpenCL implementation on OS X, 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: 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 Mini Rig, it is worth
adding the --bfl-range option.

Q: Are OpenCL kernels from other mining software useable in BFGMiner?
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, BFGMiner supports 5 FPGAs: BitForce, Icarus, ModMiner, X6500,
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. "PGA" is also used for devices built with Application-Specific
Integrated Circuits (ASICs).

Q: What is an ASIC?
A: BFGMiner currently supports 2 ASICs: Avalon and BitForce SC devices. They are
Application Specify Integrated Circuit devices and provide the highest
performance per unit power due to being dedicated to only one purpose.

Q: How do I get my BFL/Icarus/Lancelot/Cairnsmore device to auto-recognise?
A: On Linux, if the /dev/ttyUSB* devices don't automatically appear, the only
thing that needs to be done is to load the driver for them:
BFL: sudo modprobe ftdi_sio vendor=0x0403 product=0x6014
Icarus: sudo modprobe pl2303 vendor=0x067b product=0x230
Lancelot: sudo modprobe ftdi_sio vendor=0x0403 product=0x6001
Cairnsmore: sudo modprobe ftdi_sio product=0x8350 vendor=0x0403
On windows you must install the pl2303 or ftdi driver required for the device
pl2303: http://prolificusa.com/pl-2303hx-drivers/
ftdi: http://www.ftdichip.com/Drivers/VCP.htm

Q: On Linux I can see the /dev/ttyUSB* devices for my ICA/BFL/MMQ FPGA, but
BFGMiner 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 to reduce resources for mining pools at the
cost of keeping the miner in the dark and blindly transferring his mining
authority to the pool. It is a return to the problems of the old centralized
"getwork" protocol, but capable of scaling to hardware of any speed like the
standard GBT protocol. If a pool uses stratum instead of GBT, BFGMiner 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://", BFGMiner will ONLY try to
use stratum protocol mining.

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.

Luke-Jr <luke-jr+bfgminer@utopios.org>
1QATWksNFGeUJCWBrN4g6hGM178Lovm7Wh