ClusterMonkey: Last fall, I had an opportunity to test the new quad-core Intel® Xeon® 5400 processor (Harpertown) processor. As the Harpertown was in short supply, I only had two nodes (two sockets on each node for total of 16 cores) with which to run my tests. I'm not picky, however, I like to run HPC tests as this type of data is absent in the mainstream press. In particular, I am most interested in how multi-core and MPI play in the HPC space. There is plenty to discuss, but for some interesting benchmark numbers, read on.

The hardware was provided by Appro as part a white paper I was writing for SC07 (SuperComputing 2007). After some delays, like converting my temporary basement office to a real office with walls, I have finally managed to publish some of the more interesting finding from my tests. But first. a little background may be useful.

In 2006, I wrote a similar white paper using the Clovertown processor. Again, this paper was for the annual SC (SuperComputing 2006) show. When I originally ran tests on the Clovertown platform, I was not that impressed. Some codes did well, but with others, all the extra cores did not make that much difference (i.e. programs running across 8 cores on a single node only saw 2-3 effective cores). When I received the Harpertown systems, I was not sure what to expect.

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