README

https://bitcointalk.org/index.php?topic=1569129
Bounty for Cracking Bitmain S9 BMminer

Github-Pages: https://zwilla.github.io/bmminer-cgminer492


At the folder "binaries", you will find this files and these are the MD5Sum's:

MD5-Sum                                            Binary
-----------------------------------------------------------------
compile it and create them                       bmminer-api
-----------------------------------------------------------------
compile it and create them                       bmminer
-----------------------------------------------------------------
compile it and create them                       restoreConfig.sh
-----------------------------------------------------------------

The upgrade script you find at the folder "update-script"

Github-Pages: https://zwilla.github.io/bmminer-cgminer492

This is a multi-threaded multi-pool ASIC miner for Bitmain Antminer S9.

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.

Michael Padilla <michael.padilla@zwilla.de>
16L45ub3SpHZ6dYbqseip7Fv4BEJSj9xEo

If you need an invoice for your donations get it here:
https://www.zwilla.de/de/auktionen/software/donation-product-for-changing-bmminer-into-cgminer-4-9-2/

and https://zwilla.github.io/bmminer-cgminer492


NOTE: This code is licensed under the GPLv3. This means that the source to any
modifications you make to this code MUST be provided by law if you distribute
modified binaries. See COPYING for details.

Special NOTE! Read COPYING! Line 24 and 25!!!

DOWNLOADS:

https://www.zwilla.de/de/auktionen/software/donation-product-for-changing-bmminer-into-cgminer-4-9-2/

GIT TREE:

https://github.com/Zwilla/bmminer-cgminer492

Bounty thread:

https://bitcointalk.org/index.php?topic=1569129


SEE ALSO API-README, ASIC-README and FGPA-README FOR MORE INFORMATION ON EACH.

---

EXECUTIVE SUMMARY ON USAGE:

Single pool:

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

Multiple pools:

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

Single pool with a standard http proxy:

cgminer -o "http:proxy:port|http://pool:port" -u username -p password

Single pool with a socks5 proxy:

cgminer -o "socks5:proxy:port|http://pool:port" -u username -p password

Single pool with stratum protocol support:

cgminer -o stratum+tcp://pool:port -u username -p password

Solo mining to local bitcoind:

cgminer -o http://localhost:8332 -u username -p password --btc-address 15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ

The list of proxy types are:
 http:    standard http 1.1 proxy
 http0:   http 1.0 proxy
 socks4:  socks4 proxy
 socks5:  socks5 proxy
 socks4a: socks4a proxy
 socks5h: socks5 proxy using a hostname

If you compile cgminer with a version of CURL before 7.19.4 then some of the above will
not be available. All are available since CURL version 7.19.4

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


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.


---
BUILDING CGMINER FOR YOURSELF

DEPENDENCIES:
Mandatory:
	pkg-config		http://www.freedesktop.org/wiki/Software/pkg-config
	libtool			http://www.gnu.org/software/libtool/
Optional:
	curl dev library 	http://curl.haxx.se/libcurl/
	(libcurl4-openssl-dev - Must tell configure --disable-libcurl otherwise
	it will attempt to compile it in)

	curses dev library
	(libncurses5-dev or libpdcurses on WIN32 for text user interface)

	libudev dev library (libudev-dev)
	(This is only required for USB device support and is linux only)

If building from git: (more at build.md)
	autoconf
	automake



CGMiner specific configuration options:

  --enable-bitmain_C5        Compile support for BitMain Antminer S9 Multi Chain(default disabled)




---

Usage instructions:  Run "cgminer --help" to see options:

Usage: cgminer [-DdElmpPQqUsTouOchnV]

Options for both config file and command line:

--api-allow <arg>   Allow API access only to the given list of [G:]IP[/Prefix] addresses[/subnets]
--api-description <arg> Description placed in the API status header, default: cgminer version
--api-groups <arg>  API one letter groups G:cmd:cmd[,P:cmd:*...] defining the cmds a groups can use
--api-listen        Enable API, default: disabled
--api-mcast         Enable API Multicast listener, default: disabled
--api-mcast-addr <arg> API Multicast listen address
--api-mcast-code <arg> Code expected in the API Multicast message, don't use '-'
--api-mcast-des <arg> Description appended to the API Multicast reply, default: ''
--api-mcast-port <arg> API Multicast listen port (default: 4028)
--api-network       Allow API (if enabled) to listen on/for any address, default: only 127.0.0.1
--api-port <arg>    Port number of miner API (default: 4028)
--balance           Change multipool strategy from failover to even share balance
--benchfile <arg>   Run cgminer in benchmark mode using a work file - produces no shares
--benchfile-display Display each benchfile nonce found
--benchmark         Run cgminer in benchmark mode - produces no shares

--bitmain-auto      Adjust bitmain overclock frequency dynamically for best hashrate
--bitmain-cutoff    Set bitmain overheat cut off temperature
--bitmain-fan       Set fanspeed percentage for bitmain, single value or range (default: 20-100)
--bitmain-freq      Set frequency range for bitmain-auto, single value or range
--bitmain-hwerror   Set bitmain device detect hardware error
--bitmain-options   Set bitmain options baud:miners:asic:timeout:freq
--bitmain-temp      Set bitmain target temperature

--btc-address <arg> Set bitcoin target address when solo mining to bitcoind
--btc-sig <arg>     Set signature to add to coinbase when solo mining (optional)
--compact           Use compact display without per device statistics
--debug|-D          Enable debug output
--disable-rejecting Automatically disable pools that continually reject shares

--expiry|-E <arg>   Upper bound on how many seconds after getting work we consider a share from it stale (default: 120)
--failover-only     Don't leak work to backup pools when primary pool is lagging
--fix-protocol      Do not redirect to a different getwork protocol (eg. stratum)

--load-balance      Change multipool strategy from failover to quota 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-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+) (default: 1)
--quiet|-q          Disable logging output, display status and errors
--quota|-U <arg>    quota;URL combination for server with load-balance strategy quotas
--real-quiet        Disable all output
--rock-freq <arg>   Set RockMiner frequency in MHz, range 200-400 (default: 270)
--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: -1)
--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)
--sharelog <arg>    Append share log to file
--shares <arg>      Quit after mining N shares (default: unlimited)
--socks-proxy <arg> Set socks4 proxy (host:port)
--suggest-diff <arg> Suggest miner difficulty for pool to user (default: none)
--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: 90)
--text-only|-T      Disable ncurses formatted screen output
--url|-o <arg>      URL for bitcoin JSON-RPC server
--usb <arg>         USB device selection
--user|-u <arg>     Username for bitcoin JSON-RPC server
--userpass|-O <arg> Username:Password pair for bitcoin JSON-RPC server
--verbose           Log verbose output to stderr as well as status output
--widescreen        Use extra wide display without toggling
--worktime          Display extra work time debug information
Options for command line only:
--config|-c <arg>   Load a JSON-format configuration file
See example.conf for an example configuration.
--default-config <arg> Specify the filename of the default config file
Loaded at start and used when saving without a name.
--help|-h           Print this message
--ndevs|-n          Display all USB devices and exit
--version|-V        Display version and exit



Cgminer should automatically find all of your Bitmain Antminer S9 ASICs.

---

SETTING UP

Open your miners frontend and choose the options there

WHILE RUNNING from SSh Terminal:

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

 [U]SB management [P]ool management [S]ettings [D]isplay options [Q]uit


U gives you:

[S]ummary of device information
[E]nable device
[D]isable device
[U]nplug to allow hotplug restart
[R]eset device USB
[L]ist all known devices
[B]lacklist current device from current instance of cgminer
[W]hitelist previously blacklisted device
[H]otplug interval (0 to disable)


P gives you:

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


S gives you:

[Q]ueue: 1
[S]cantime: 60
[E]xpiry: 120
[W]rite config file
[C]gminer restart


D gives you:

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


Q quits the application.


The running log shows output like this:

 [2016-11-09 11:11:41] Accepted 01b3bde7 Diff 382345134/342345150 BC5 1 pool 0
 [2016-11-09 11:11:49] Accepted 015df995 Diff 392345612/342345150 BC5 1 pool 0
 [2016-11-09 11:11:50] Accepted 01163b68 Diff 372345456/342345150 BC5 1 pool 0
 [2016-11-09 11:11:53] Accepted 9f745840 Diff 352345786/342345150 BC5 1 pool 0

The 8 byte hex value are the 1st nonzero bytes of the share being submitted to
the pool. The 2 diff values are the actual difficulty target that share reached
followed by the difficulty target the pool is currently asking for.


DISPLAY:

The display is roughly split into two portions, the top status window and the
bottom scrolling log window.


STATUS WINDOW
The status window is split into overall status and per device status.

Overall status:

The output line shows the following:
 (5s):2.469T (1m):2.677T (5m):2.040T (15m):1.014T (avg):2.733Th/s

These are exponentially decaying average hashrates over 5s/1m/5m/15m and an
average since the start.

Followed by:
 A:290391  R:5101  HW:145  WU:37610.4/m

Each column is as follows:
A:  The total difficulty of Accepted shares
R:  The total difficulty of Rejected shares
HW:  The number of HardWare errors
WU:  The Work Utility defined as the number of diff1 shares work / minute
     (accepted or rejected).

alternating with:
 ST: 22  SS: 0  NB: 2  LW: 356090  GF: 0  RF: 0

ST is STaged work items (ready to use).
SS is Stale Shares discarded (detected and not submitted so don't count as rejects)
NB is New Blocks detected on the network
LW is Locally generated Work items
GF is Getwork Fail Occasions (server slow to provide work)
RF is Remote Fail occasions (server slow to accept work)

Followed by:
 Connected to pool.com diff 3.45K with stratum as user me

The diff shown is the current vardiff requested by the pool currently being
mined at.

Followed by:
Block: ca0d237f...  Diff:5.01G  Started: [00:14:27]  Best share: 1.18M

This shows a short stretch about the current block, when the new block started,
and the all time best difficulty share you've found since starting cgminer
this time.

Per device status:

 6: HFS Random  : 645MHz  85C  13% 0.79V  | 2.152T / 1.351Th/s

Each column is as follows:
Temperature (if supported)
Fanspeed (if supported)
Voltage (if supported)

A 5 second exponentially decaying average hash rate
An all time average hash rate

alternating with

 6: HFS Random  : 645MHz  86C  13% 0.80V  | A:290348 R:1067 HW:88 WU:18901.8/m

The total difficulty of accepted shares
The total difficulty of rejected shares
The number of hardware erorrs
The work utility defined as the number of diff1 shares work / minute


LOG WINDOW

All running information is shown here, usually share submission results and
block update notifications, along with device messages and warnings.

 [2014-03-29 00:24:09] Accepted 1397768d Diff 3.35K/2727 HFS 0 pool 0
 [2014-03-29 00:24:13] Stratum from pool 0 detected new block


---
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 on a quota basis. By default, all
pools are allocated equal quotas unless specified with --quota. This
apportioning of work is based on work handed out, not shares returned so is
independent of difficulty targets or rejected shares. While a pool is disabled
or dead, its quota is dropped until it is re-enabled. Quotas are forward
looking, so if the quota is changed on the fly, it only affects future work.
If all pools are set to zero quota or all pools with quota are dead, it will
fall back to a failover mode. See quota below for more information.

The failover-only flag has special meaning in combination with load-balance
mode and it will distribute quota back to priority pool 0 from any pools that
are unable to provide work for any reason so as to maintain quota ratios
between the rest of the pools.

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.


---
QUOTAS

The load-balance multipool strategy works off a quota based scheduler. The
quotas handed out by default are equal, but the user is allowed to specify any
arbitrary ratio of quotas. For example, if all the quota values add up to 100,
each quota value will be a percentage, but if 2 pools are specified and pool0
is given a quota of 1 and pool1 is given a quota of 9, pool0 will get 10% of
the work and pool1 will get 90%. Quotas can be changed on the fly by the API,
and do not act retrospectively. Setting a quota to zero will effectively
disable that pool unless all other pools are disabled or dead. In that
scenario, load-balance falls back to regular failover priority-based strategy.
While a pool is dead, it loses its quota and no attempt is made to catch up
when it comes back to life.

To specify quotas on the command line, pools should be specified with a
semicolon separated --quota(or -U) entry instead of --url. Pools specified with
--url are given a nominal quota value of 1 and entries can be mixed.

For example:
--url poola:porta -u usernamea -p passa --quota "2;poolb:portb" -u usernameb -p passb
Will give poola 1/3 of the work and poolb 2/3 of the work.

Writing configuration files with quotas is likewise supported. To use the above
quotas in a configuration file they would be specified thus:

"pools" : [
        {
                "url" : "poola:porta",
                "user" : "usernamea",
                "pass" : "passa"
        },
        {
                "quota" : "2;poolb:portb",
                "user" : "usernameb",
                "pass" : "passb"
        }
]


---
SOLO MINING

Solo mining can be done efficiently as a single pool entry or a backup to
any other pooled mining and it is recommended everyone have solo mining set up
as their final backup in case all their other pools are DDoSed/down for the
security of the network. To enable solo mining, one must be running a local
bitcoind/bitcoin-qt or have one they have rpc access to. To do this, edit your
bitcoind configuration file (bitcoin.conf) with the following extra lines,
using your choice of username and password:

rpcuser=username
rpcpassword=password

Restart bitcoind, then start cgminer, pointing to the bitcoind and choose a
btc address with the following options, altering to suit their setup:

cgminer -o http://localhost:8332 -u username -p password --btc-address 15qSxP1SQcUX3o4nhkfdbgyoWEFMomJ4rZ

Note the http:// is mandatory for solo mining.

---
LOGGING

cgminer will log to stderr if it detects stderr is being redirected to a file.
To enable logging simply add 2>logfile.txt to your command line and logfile.txt
will contain the logged output at the log level you specify (normal, verbose,
debug etc.)

In other words if you would normally use:
./cgminer -o xxx -u yyy -p zzz
if you use
./cgminer -o xxx -u yyy -p zzz 2>logfile.txt
it will log to a file called logfile.txt and otherwise work the same.

There is also the -m option on linux which will spawn a command of your choice
and pipe the output directly to that command.

The WorkTime details 'debug' option adds details on the end of each line
displayed for Accepted or Rejected work done. An example would be:

 <-00000059.ed4834a3 M:X D:1.0 G:17:02:38:0.405 C:1.855 (2.995) W:3.440 (0.000) S:0.461 R:17:02:47

The first 2 hex codes are the previous block hash, the rest are reported in
seconds unless stated otherwise:
The previous hash is followed by the getwork mode used M:X where X is one of
P:Pool, T:Test Pool, L:LP or B:Benchmark,
then D:d.ddd is the difficulty required to get a share from the work,
then G:hh:mm:ss:n.nnn, which is when the getwork or LP was sent to the pool and
the n.nnn is how long it took to reply,
followed by 'O' on it's own if it is an original getwork, or 'C:n.nnn' if it was
a clone with n.nnn stating how long after the work was recieved that it was cloned,
(m.mmm) is how long from when the original work was received until work started,
W:n.nnn is how long the work took to process until it was ready to submit,
(m.mmm) is how long from ready to submit to actually doing the submit, this is
usually 0.000 unless there was a problem with submitting the work,
S:n.nnn is how long it took to submit the completed work and await the reply,
R:hh:mm:ss is the actual time the work submit reply was received

If you start cgminer with the --sharelog option, you can get detailed
information for each share found. The argument to the option may be "-" for
standard output (not advisable with the ncurses UI), any valid positive number
for that file descriptor, or a filename.

To log share data to a file named "share.log", you can use either:
./cgminer --sharelog 50 -o xxx -u yyy -p zzz 50>share.log
./cgminer --sharelog share.log -o xxx -u yyy -p zzz

For every share found, data will be logged in a CSV (Comma Separated Value)
format:
    timestamp,disposition,target,pool,dev,thr,sharehash,sharedata
For example (this is wrapped, but it's all on one line for real):
    1335313090,reject,
    ffffffffffffffffffffffffffffffffffffffffffffffffffffffff00000000,
    http://localhost:8337,ASC0,0,
    6f983c918f3299b58febf95ec4d0c7094ed634bc13754553ec34fc3800000000,
    00000001a0980aff4ce4a96d53f4b89a2d5f0e765c978640fe24372a000001c5
    000000004a4366808f81d44f26df3d69d7dc4b3473385930462d9ab707b50498
    f681634a4f1f63d01a0cd43fb338000000000080000000000000000000000000
    0000000000000000000000000000000000000000000000000000000080020000

---

BENCHMARK

The --benchmark option hashes a single fixed work item over and over and does
not submit shares to any pools.

The --benchfile <arg> option hashes the work given in the file <arg> supplied.
The format of the work file is:
version,merkleroot,prevhash,diffbits,noncetime
Any empty line or any line starting with '#' or '/' is ignored.
When it reaches the end of the file it continues back at the top.

The format of the data items matches the byte ordering and format of the
the bitcoind getblock RPC output.

An example file containing bitcoin block #1 would be:

# Block 1
1,0e3e2357e806b6cdb1f70b54c3a3a17b6714ee1f0e68bebb44a74b1efd512098,00000000001
9d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f,1d00ffff,1231469665

However, the work data should be one line without the linebreak in the middle

If you use --benchfile <arg>, then --benchfile-display will output a log line,
for each nonce found, showing the nonce value in decimal and hex and the work
used to find it in hex.

---

RPC API

For RPC API details see the API-README file

---

FAQ

Q: Help, I've started cgminer and everything reads zero!?
A: Welcome to bitcoin mining. Your computer by itself cannot mine bitcoin no
matter how powerful it is. You have to purchase dedicated mining hardware
called ASICs to plug into your computer. See Q regarding ASICs below.

Q: I have multiple USB stick devices but I can't get them all to work at once?
A: Very few USB hubs deliver the promised power required to run as many devices
as they fit if all of them draw power from USB.

Q: I've plugged my devices into my USB hub but nothing shows up?
A: RPis and Windows have incomplete or non-standard USB3 support so they may
never work. It may be possible to get a USB3 hub to work by plugging it into
a USB2 hub. When choosing a hub, USB2 hubs are preferable whenever possible
due to better support all round.

Q: Can I mine on servers from different networks (eg xxxcoin 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 configure cgminer to mine with different login credentials or pools
for each separate device?
A: No.

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. Also -O2 is capital o 2, not zero 2.

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: 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 devices 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. There is far more detail in the API output than can be reasonably
displayed on the small console window, and using an external interface such
as miner.php is much more useful for setups with many devices.

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.

Q: What happened to CPU and GPU mining?
A: Their efficiency makes them irrelevant in the bitcoin mining world today
and the author has no interest in supporting alternative coins that are better
mined by these devices.

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 and operating system.

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 in terms of performance. It comes down to choice of
operating system for their various features and your comfort level. However
linux is the primary development platform and is virtually guaranteed to be
more stable.

Q: My network gets slower and slower and then dies for a minute?
A; Try the --net-delay option if you are on a getwork or GBT server. This does
nothing with stratum mining.

Q: How do I tune for p2pool?
A: It is also recommended to use --failover-only since the work is effectively
like a different block chain, and not enabling --no-submit-stale. If mining with
a BFL (fpga) minirig, it is worth adding the --bfl-range option.

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: Cgminer supports 3 FPGAs: BitForce, Icarus and ModMiner.
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: What is an ASIC?
A: They are Application Specify Integrated Circuit devices and provide the
highest performance per unit power due to being dedicated to only one purpose.
They are the only meaningful way to mine bitcoin today.

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: My keyboard input momentarily pauses or repeats keys every so often on
windows while mining?
A: The USB implementation on windows can be very flaky on some hardware and
every time cgminer looks for new hardware to hotplug it it can cause these
sorts of problems. You can disable hotplug with:
--hotplug 0

Q: What should my Work Utility (WU) be?
A: Work utility is the product of hashrate * luck and only stabilises over a
very long period of time. Assuming all your work is valid work, bitcoin mining
should produce a work utility of approximately 1 per 71.6MH. This means at
5GH you should have a WU of 5000 / 71.6 or ~ 69. You cannot make your machine
do "better WU" than this - it is luck related. However you can make it much
worse if your machine produces a lot of hardware errors producing invalid work.


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