using an [AMD] Opteron 6234 6 module / 12 core processor
This score for the
6-Core AMD Opteron @ 2.4GHz 137,913 req/s falls short of our 850,000 req/s on an Intel
6-Core Xeon W3680 @ 3.33GHz (with a 100-byte static file).
Besides the differences of each architure performance*, the problem for G-WAN comes on AMD CPUs from the fact that we did not have access to any of those CPUs (all our machines are equipped with Intel CPUs).
Thanks to recent AMD user reports, we have found that the number of detected CPU Cores for AMD CPUs is twice the actual number. This is due to the fact that AMD has its own set of
CPUID codes and return values - which differ from Intel's.
This AMD CPU Core mis-detection leads to obvious CPU cache conflicts - the problems supposed to be resolved by G-WAN.
For now, by using
./gwan -w 6 you can force any given multicore setting, bypassing
the G-WAN automatic detection when needed.
In your case, your should be using 6 physical CPU Cores rather than the 12 wrongly used by G-WAN. This is what you can do right now (and you will most probably get much higher results with your benchamrks by just doing that).
We will issue an AMD workaround in the next release to make sure that no more manual tweaking is needed.