Linux Shootout: Opteron 150 vs. Xeon 3.6 Nocona

"The 'SP' benchmark calculates the scalar product (dot product) of 2 vectors ranging in size from 16 elements to 1048576 elements for both single and double-precision floats.  Although the Gflops/sec. for every vector length is recorded (in the resulting output log file), the average of all these values is reported. This benchmark is indicative of the performance of many raw floating-point data processing apps (movie format conversion, MP3 extraction, etc.)"

Note that we ran the P4 optimized binaries on the Nocona, which did not provide x86-64 enhancements.  Running the AMD64 binaries on the Xeon yielded poor results. The P4 Opstone binaries are the only 32-bit binaries used in this analysis.

Below is the SSP benchmark, as explained by the author:

"The 'ssp' benchmark also calculates the scalar product of 2 vectors, except that these vectors are sparsely populated (only the non-zero value elements are stored) ranging from a 'loading factor' (non-zero/zero elements) of 0.000001 to 0.01 for both single and double-precision floats.  Since the data is not contiguous in memory, the performance is much lower than regular 'sp' and is measured in Mflops/sec.  There is not much difference in performance between different loading factors as this benchmark really challenges the ability of the processor to perform short bursts of calculations coupled with lots of conditional testing.  It is this reason that the P4 with its longer pipeline does not generally perform as well as the Athlon64.  This benchmark is indicative of the performance of many 3D games as the processing is similar (short bursts of calculations with numerous conditional testing)"