>Hyper threading. It's usually not recommended to enable it on >PostgreSQL servers. On most servers, you can disable it directly in >the BIOS. Maybe for specific usage scenarios, but that's generally not been my experience with relatively recent versions of PG. We ran some tests with pgbench, and averaged 10% or more performance improvement. Now, I agree pgbench isn't the most realistic performance, but we did notice a slight improvement in our application performance too. Also, here's some benchmarks that were posted earlier by the folks at tweakers.net also showing hyperthreading to be faster: http://tweakers.net/reviews/646/10 I'm not sure if it's dependent on OS- our tests were on BSD 5.x and PG 7.4 and 8.0/8.1 and were several months ago, so I don't remember many more specifics than that. So, not saying it's a best practice one way or another, but this is pretty easy to test and you should definitely try it out both ways for your workload. - Bucky
