The same test WUs on AMD 64 3200+ (Winchester) (64-bit Win2003)
It seems SSE2 32-bit - the best and 2.4 version is slightly faster than 2.4V new one.
In first test former 2.4 SSE2 app was faster, in other tests 2.4 SSEa (from Crunch3r's site) was faster.
So, according this test, KWSN_2.4_MB_SSE2A.exe from 2.4_Windows_x32_SSE2_AMD archive - fastest choice for Athlon 64
(and 64-bit OS of course)
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