gpuOwl is a Mersenne (see http://mersenne.org/ ) primality tester implemented in OpenCL, that works well on AMD GPUs.
gpuOwl implements the PRP test with a powerful self-validating algorithm that protects agains errors. gpuOwl uses FFT transforms of size 8M and 16M, and is best used with Mersenne exponents in the vicinity of 150M and 300M.
- worktodo.txt : contains exponents to test, one entry per line
- results.txt : contains the results
- N.owl : the most recent checkpoint for exponent ; will resume from here
- N-prev.owl : the previous checkpoint, to be used if N.ll is lost or corrupted
- N.iteration.owl : a persistent checkpoint at the given iteration
The lines in worktodo.txt must be of one of these forms:
- 70100200
- PRP=FCECE568118E4626AB85ED36A9CC8D4F,1,2,77936867,-1,75,0
The first form indicates just the exponent to test, while the form starting with PRP indicates both the exponent and the assignment ID (AID) from PrimeNet.
- Make sure that the gpuowl.cl file is in the same folder as the executable
- Get "PRP smallest available first time tests" assignments from GIMPS Manual Testing ( http://mersenne.org/ ).
- Copy the assignment lines from GIMPS to a file named 'worktodo.txt'
- Run gpuowl. It prints progress report on stdout and in gpuowl.log, and writes result lines to results.txt
- Submit the result lines from results.txt to http://mersenne.org/ manual testing.
To build simply invoke "make" (or look inside the Makefile for a manual build).
- a C++ compiler (e.g. gcc, clang)
- an OpenCL implementation (which provides the libOpenCL library). Recommended: an AMD GPU with ROCm 1.7.
Simply start GpuOwl with any valid exponent, and the built-in error checking kicks in, validating the computation. If you start seeing output lines with "OK", than it's working correctly. "EE" lines indicate computation errors.
