The Athlon64/Opteron have SSE2 instruction support, but Prime95 performance lags the Intel chips significantly. A single instance of Prime95 on one of our Opteron 270 (2.0GHz dual-core) performs at about 2/3 of the speed of my P4 3.0 Ghz (which would be very similar to a single instance on a 3.0 GHz Pentium D). See benchmarks below.
That said, there are plenty of other reasons to go with the AMD; it has better per-core integer performance as measured by SPECint2000 (AMD = 1347, Intel = 1151), as well as better power utilization. I don't think losing 33% of Prime95 performance is something that would change my buying decisions. Dual Core AMD Opteron(tm) Processor 270 CPU speed: 1991.22 MHz CPU features: RDTSC, CMOV, Prefetch, 3DNow!, MMX, SSE, SSE2 L1 cache size: 64 KB L2 cache size: 1024 KB L1 cache line size: 64 bytes L2 cache line size: 64 bytes L1 TLBS: 32 L2 TLBS: 512 Prime95 32-bit version 24.14, RdtscTiming=1 Best time for 512K FFT length: 23.367 ms. Best time for 640K FFT length: 30.470 ms. Best time for 768K FFT length: 36.987 ms. Best time for 896K FFT length: 44.190 ms. Best time for 1024K FFT length: 49.333 ms. Best time for 1280K FFT length: 62.729 ms. Best time for 1536K FFT length: 76.737 ms. Best time for 1792K FFT length: 92.937 ms. Best time for 2048K FFT length: 103.536 ms. Best time for 2560K FFT length: 135.643 ms. Best time for 3072K FFT length: 165.764 ms. Best time for 3584K FFT length: 199.911 ms. Best time for 4096K FFT length: 222.695 ms. Best time for 58 bit trial factors: 5.994 ms. Best time for 59 bit trial factors: 5.998 ms. Best time for 60 bit trial factors: 5.974 ms. Best time for 61 bit trial factors: 5.999 ms. Best time for 62 bit trial factors: 10.739 ms. Best time for 63 bit trial factors: 10.779 ms. Best time for 64 bit trial factors: 13.925 ms. Best time for 65 bit trial factors: 13.824 ms. Best time for 66 bit trial factors: 13.855 ms. Best time for 67 bit trial factors: 13.784 ms. Intel(R) Pentium(R) 4 CPU 3.00GHz CPU speed: 2998.71 MHz CPU features: RDTSC, CMOV, Prefetch, MMX, SSE, SSE2 L1 cache size: 8 KB L2 cache size: 512 KB L1 cache line size: 64 bytes L2 cache line size: 128 bytes TLBS: 64 Prime95 32-bit version 24.13, RdtscTiming=1 Best time for 512K FFT length: 14.636 ms. Best time for 640K FFT length: 18.935 ms. Best time for 768K FFT length: 23.350 ms. Best time for 896K FFT length: 27.641 ms. Best time for 1024K FFT length: 30.895 ms. Best time for 1280K FFT length: 39.816 ms. Best time for 1536K FFT length: 48.994 ms. Best time for 1792K FFT length: 58.074 ms. Best time for 2048K FFT length: 65.641 ms. Best time for 2560K FFT length: 84.693 ms. Best time for 3072K FFT length: 108.384 ms. Best time for 3584K FFT length: 127.163 ms. Best time for 4096K FFT length: 146.062 ms. Best time for 58 bit trial factors: 9.943 ms. Best time for 59 bit trial factors: 9.944 ms. Best time for 60 bit trial factors: 9.863 ms. Best time for 61 bit trial factors: 9.982 ms. Best time for 62 bit trial factors: 10.721 ms. Best time for 63 bit trial factors: 10.958 ms. Best time for 64 bit trial factors: 13.267 ms. Best time for 65 bit trial factors: 13.104 ms. Best time for 66 bit trial factors: 13.013 ms. Best time for 67 bit trial factors: 13.061 ms. _______________________________________________ Prime mailing list [email protected] http://hogranch.com/mailman/listinfo/prime
