CPU "differences"

It is a known fact that every CPU model is different with regard to speed, cache sizes, memory controllers, etc. FAH WUs also differ, with varying sizes and differing computational methods used. Therefore it is clear that different CPUs will compute WUs at different rates.

All CPU client WUs are benchmarked and scored on an Intel P4C @ 2.8 GHz running Linux, with SSE2 and HyperThreading disabled. Therefore every other CPU will achieve greater or fewer points per day running those same projects. There have been numerous flame-wars surrounding this issue ("I get less points than my neighbour!"), but a better, solid, and simpler (KISS) method has yet to be proposed. For the foreseeable future, the scoring system will remain as it is.

Note: Each CPU will process the same data a little differently. This is perfectly normal, but this can sometimes introduce errors that lead to an EUE.

Benchmark machines

CPU client: Intel P4C Northwood @ 2.8GHz on Linux, with SSE2 and HyperThreading disabled. Benchmark speed: 110PPD, or 220PPD for big WUs. SMP client: Mac Pro with two Intel Xeon 5140 Woodcrest dual-core CPUs with 4MB cache. (all extensions enabled). Benchmark speed: 1760PPD (includes big WU bonus). GPU client: ATI HD3850 (for both ATI and nVidia units) fed by a 2.16GHz AMD Athlon 64 X2 4000+. Benchmark speed: 1500PPD. PS3 client: A PS3 system, which are all homogenous at present, so all should perform about the same. However, small variances in WUs will still make performance numbers change ever so slightly. Benchmark PPD: 900.

Reference Links
 * fahinfo.org Folding@Home Project information site