[CentOS] Hyper Threading Feature

Thu Apr 12 20:22:21 UTC 2012
John R Pierce <pierce at hogranch.com>

On 04/12/12 1:06 PM, Scott Silva wrote:
> As far as I know, hyper-threading is sort of like processor emulation... As
> long as the extra threads are hitting different registers, it can help. But if
> it needs any floating point, the thread will wait until it has full access...
> It seems to be hit or miss on how much it will hurt/help a load...

database work is almost never floating point bound, even if the SQL is 
full of FP code, for every FP machine operation there's 1000s of integer 
operations, for which the HT does quite well at.

HT is almost always a win-win on everything that can use lots of 
threads, other than scientific processing or multimedia encoding (video 
transcoding etc)


-- 
john r pierce                            N 37, W 122
santa cruz ca                         mid-left coast