We tested the two new processor platforms and below are our findings:


This year has brought big advances to the CPU industry with the arrival of the Intel Xeon 5500 series "Nehalem" and the AMD Opteron 2400 series "Istanbul". While many different benchmarks have been published comparing both systems, they all have seemed to fall a bit short in showing an accurate No code has to be inserted here.

Conclusion:

When viewing HPL results there are two interesting figures to look at: the Actual Peak which is what is measured by the benchmark and comparing this number to what the theoretical best performance the processor can provide (Theoretical Peak). This is referred to as the efficiency. We've also included the rough prices of the systems and a GFLOP per dollar rating. As you can see, AMD beats Intel on GFLOPS per dollar and peak performance, but loses on overall efficiency. This shows us that while the 6 cores per CPU that AMD Istanbul is offering provides better raw horsepower, the overall system architecture is not as balanced as Intel's Nehalem. The lower efficiency rating is most likely caused by the lack of memory bandwidth, and increased cache snoops in the Istanbul system. The CPU's sit idle for a longer period of time while waiting for data from main memory and while checking for cache hits in all of the system's 12 cores . Memory bandwidth can have a huge impact on overall system performance, and is beyond the scope of this document--it will be covered in a latter post.

So, while the Nehalem may have the best performance per core and higher efficiency, the Istanbul does a good job of making up for its deficiencies by adding additional cores. When choosing a system architecture for your next cluster, HPL should be only one of the benchmarks you use in your evaluation, We will be updating this blog with more performance results and benchmarks over the next couple of months. If you have any ideas or code that you'd like to see tested, please let us know -- send an email to scorder at advancedclustering dot com