Re: High CPU Load - Mailing list pgsql-performance

From Bucky Jordan
Subject Re: High CPU Load
Date
Msg-id 78ED28FACE63744386D68D8A9D1CF5D4209999@MAIL.corp.lumeta.com
Whole thread Raw
In response to Re: High CPU Load  ("Guillaume Smet" <guillaume.smet@gmail.com>)
List pgsql-performance
>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.
Weran some tests with pgbench, and averaged 10% or more performance improvement. Now, I agree pgbench isn't the most
realisticperformance, 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
Idon'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
itout both ways for your workload. 

- Bucky


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