AMD, Intel, and PostgreSQL

A few weeks ago I presented an updated 2010 version of my talk on database hardware benchmarking at PG East. CPU and memory performance are particularly important for a PostgreSQL database, because every individual query runs as a single process.  Therefore, the speed of your fastest core determines how fast any one query can execute at, and in modern systems that’s quite likely to bottleneck based on memory speed.

One of the things that’s obvious from recent memory speed results is that all of AMD’s processors have been stuck in a distant second place for almost 18 months now.  While AMD continues to use DDR2-800, Intel’s “Nehalem” processors, shipping in volume since early 2009, have been adopting increasingly fast DDR3 in good performing multi-channel configurations–the exact area AMD used to be the king of.  In the normal single or dual core server configuration, Intel has had such a lead that it’s been impossible to recommend them for anything but a completely disk-bound workload for some time now.

Like many commentaries on PC hardware, my suggestions were only cutting edge for…drumroll please…one week.  Basically, the minute my talk was over, AMD released a new line of 12-core processors that use DDR-1333, and they’ve closed most of the gap with Intel again.  In raw memory performance, they’ve increased memory performance 130% over their earlier design, and actually pulled ahead on that low-level benchmark.

How about database workloads?  One of the supporting bits of data I pointed to for how much the CPU/memory performance could impact a database workload were the Oracle Charbench “Calling Circle” OLTP benchmark results run by AnandTech.  Their new Calling Circle results show where the market is at now.  Intel still owns the top part of the market, but AMD’s results with their Opteron 6174 are back to respectable.

If you have a workload where more cores is what you need most of the time, the new processors from AMD could be just what you’re looking for.  Fast enough for single queries again, scaling up quite well to handle workloads with many clients.  Memory technology really matters, and you should make sure to note (and benchmark yourself!) the speed of any system you’re considering or using to make sure it’s appropriate for your workload.

How long will this situation continue?  Well, Intel’s next big server processor refresh, codenamed Sandy Bridge, is expected by the end of 2010.  Progress marches on.