How to disable Hyperthreading?

[MarS]

I'm on one of the x3470 machines with ubuntu 10.4 LTS and I was wondering if anyone knew how to disable hyperthreading? I'm only running a mysql server and a minecraft server which is entirely single threaded, and what I've gathered from weeks of research is that disabling this feature should improve performance. So, any pointers would be great I'm also googling it but wouldn't mind someones voice of experience. Thanks!

[Edge100x]

Disabling hyperthreading won't increase performance by any noticeable amount (not more than 1 or 2%, if even that) on i7+ machines, but it made a big difference for the old P4s. We've done testing here on this and I would recommend against changing it.

If you strongly wish it to be turned off, please contact us -- it's a change that generally needs to be made in the BIOS.