CPUMiner 2.5.0 Setup and Optimization Guide

Current Version: 2.5.0 (Jun 22, 2017) – Changelog
Source tarball: https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0.tar.gz
Binaries for Windows:
https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0-win32.zip (32-bit)
https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0-win64.zip  (64-bit)
Binaries for Linux:
https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0-linux-x86.tar.gz (x86)
https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0-linux-x86_64.tar.gz (x86-64)
Binaries for Mac OS X:
https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0-osx32.zip (32-bit)
https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0-osx64.zip (64-bit)

SHA-256 Checksums

ea16761a952b8f0fbba22fd16d48bb5e20abc48a10af99a00c70c332b3cb54f5  pooler-cpuminer-2.5.0.tar.gz
c385a7a73730b40548c5c658aa476dd4a95d4629d1c159a1ef830a0068c1c744  pooler-cpuminer-2.5.0-linux-x86.tar.gz
bf390ab6b801536aca3f8ece535ee71550afdc984ea5de67195b15ff3c248539  pooler-cpuminer-2.5.0-linux-x86_64.tar.gz
b45c7838aec8f704ef6700d5feb27f8e6c798bb0a42ce847bf3b203188d4183e  pooler-cpuminer-2.5.0-osx32.zip
c86ba412b3c10163f4623272e5ff746c57373ef403251472ef41a9a84ce33332  pooler-cpuminer-2.5.0-osx64.zip
dfa8713404b709f84550dda1af642ca49af72a4ec0e333eb9c3f797ae2554e2e  pooler-cpuminer-2.5.0-win32.zip
4cf4af2ae1d1a42c97b88ca91cfa1b49851efecbb62d6fafe0a5152ffd47fde1  pooler-cpuminer-2.5.0-win64.zip

Best Hardware / CPUs to use for CPUMiner

AMD Athlon X4 860K with 95W Thermal Solution 3.7 GHz Socket FM2+ AD860KXBJASBX

Intel Core i7-2600K Quad-Core Processor 3.4 Ghz 8 MB Cache LGA 1155 – BX80623I72600K

Basic usage examples

$ ./minerd –url=https://myminingpool.com:9332 –userpass=my.worker:password
$ ./minerd –url=stratum+tcp://myminingpool.com:3333 –userpass=my.worker:password

For more information:

$ ./minerd –help

Building instructions
Installing dependencies for building on Debian, Ubuntu and other APT-based distros:

$ sudo apt-get install make libcurl4-openssl-dev

Installing dependencies for building on Fedora, RHEL, CentOS and other yum-based distros:

$ sudo yum install gcc make curl-devel

Installing dependencies for building on OpenSUSE and other ZYpp-based distros:

$ sudo zypper in gcc make libcurl-devel

Recipe for building on Linux:

$ wget https://github.com/pooler/cpuminer/releases/download/v2.5.0/pooler-cpuminer-2.5.0.tar.gz
$ tar xzf pooler-cpuminer-*.tar.gz
$ cd cpuminer-*
$ ./configure CFLAGS=”-O3″
$ make

FAQ / Troubleshooting

Q: Should I call this miner “cpuminer” or “minerd”?
A: The software package is called “cpuminer”. “minerd” (“miner daemon”) is just the name of the executable file provided by the package.

Q: My antivirus flags the Windows binary as malware.
A: That’s a known false positive. More information here.

Q: When I click on minerd.exe a black window flashes up and then disappears.
A: This is a command-line application, it has no graphical interface. You’ll need to learn how to use the command line interface (CLI) of your operating system first.

Q: Can I mine (insert your cryptocoin here) with this miner?
A: Only if its proof-of-work algorithm is scrypt or SHA-256d. This miner does not currently support other algorithms such as Keccak, scrypt-jane, X11, etc. Forks of this project may provide additional algorithms, but I do not maintain them and they are not discussed here, so if you have questions about them please contact their authors.

Q: When running configure I get the error “C compiler cannot create executables”.
A: Make sure you typed CFLAGS="-O3" with a big O, not with a zero.

Q: autogen.sh dies with “error: possibly undefined macro: AC_MSG_ERROR”.
Q: configure chokes on something like “LIBCURL_CHECK_CONFIG(, 7.15.2, ,'”.
A: Make sure you have installed the development package for libcurl. If you have and you’re still getting the error when compiling from git, try compiling from tarball instead.

Q: I’m trying to connect to a Stratum server, but I get “HTTP request failed: Empty reply from server”.
A: Make sure you specified the correct protocol in the server URL (stratum+tcp://).

Q: Is there any command-line option I can play with to make it mine faster?
A: No. The miner automatically picks the best settings for the CPU it is run on.

Q: What’s the difference between the two algorithms, scrypt and sha256d?
A: They are completely different proof-of-work algorithms. You must use scrypt for Litecoin, and you must use sha256d for Bitcoin. The default algorithm is scrypt, so for Bitcoin mining you have to specify --algo=sha256d.

Q: Will this miner use a lot of RAM when using the scrypt algorithm?
A: No, that’s a GPU thing.

Q: How do I make the miner write its output to a file instead of printing it to the screen?
A: Just redirect the standard error stream to file:

minerd [OPTIONS] 2> myfile

You may also want to use the --quiet/-q option to disable the per-thread hashmeter.
On *nix, you probably also want to use the --background/-B option to fork in the background.

Original post (December 19, 2011) follows. Please note that most of the technical details are now outdated.

I have recently rewritten the heart of the scrypt hashing function used by the jgarzik/ArtForz cpuminer in assembly language, to see if this could bring some more speed. Apparently it did. Smiley
The source code is now available at GitHub:
The build process for Linux should be the same as before.

In the new code I tried to take full advantage of SSE2 instructions, which are available since the Pentium 4. Unfortunately, AMD’s implementation of these instructions is not as fast as Intel’s… well, ok, sadly it’s nearly two times slower. For this reason, I had to write separate versions of the hashing functions. You don’t need to worry about this, though, since the new function should be able to auto-detect your cpu and automatically select the best algorithm.

Long polling patch
This release also includes a new –timeout option that I originally added to solve a problem with long polling. Apparently the LP thread doesn’t behave nicely under certain network conditions, as reported by various users. So, if you experienced high stale rates with the previous miner, you should definitely try out this new version.
Many thanks to SockPuppet, aka shawnp0wers, who helped me nail down the issue!

Some Technical Details
The current release includes four different implementations of the scrypt core, each one designed for a different hardware.

  • A fallback plain x86 version, to be used when SSE2 instructions are not available (Pentium III, Athlon XP and earlier processors).
  • A 32-bit version using SSE2, for use on the Pentium 4, Pentium M, Core, Atom, plus all 64-bit cpus running in a 32-bit OS.
  • A 64-bit version for Intel processors, i.e. Core 2, i3, i5, i7. This version can in most cases double the speed of the previous miner.
  • A 64-bit version for AMD processors, i.e. Athlon 64, Phenom, Sempron and the like. The speed increase here can range from 5% to 80%.

The first two versions only get compiled in the 32-bit miner, the last two only in the 64-bit miner. The miner uses the CPUID instruction to choose which version to use.

Compiler Flags
One cool aspect of assembly code is that users no more need to play with compiler flags to get the best performance. Configuring the build with just CFLAGS=”-O3″ is now more than enough to get efficient code. This also means that we no more need separate specialized binaries for Intel and AMD cpus. Just a 32-bit and a 64-bit version.

Final Notes
It is important for Litecoin that everybody has access to the most efficient mining software!
Someone might worry about the effect of this release on market prices, but consider this: if everybody starts using the new miner, the hash rate will go up, but so will difficulty, so nothing will ultimately change. I actually think this new miner will be very beneficial to Litecoin, because it should make mining easier for beginners (see compiler flags).

One big plus of Litecoin is that everybody can participate. Well, consider this: now you can effectively mine on an Atom!

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