Re: Hyperthreading

From: Brooks Davis <brooks_at_one-eyed-alien.net>
Date: Fri, 27 Jun 2003 16:53:47 -0700
On Fri, Jun 27, 2003 at 06:39:12PM -0500, Glenn Johnson wrote:
> Thanks.  I had read the smp manual page.  I know _how_ to enable HTT; I
> was wondering whether I _should_ enable it.  It seems the answer is that
> it is not beneficial in its current state because the scheduler does not
> yet differentiate between physical and logical processors.

It's more complicated then that.  For many users, it's true that HTT is
not useful due to the scheduling issues, but for some applications where
you keep all the CPUs busy, it does help.  Somewhat suprisingly,
SETI_at_Home performs better with HTT enabled then without.  The individual
workunits take longer to process, but the overall throughput is better
(4 workunits every 6hrs instead of 2 workunits every 4hrs).

-- Brooks

-- 
Any statement of the form "X is the one, true Y" is FALSE.
PGP fingerprint 655D 519C 26A7 82E7 2529  9BF0 5D8E 8BE9 F238 1AD4

Received on Fri Jun 27 2003 - 14:53:50 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:37:13 UTC