Hyperthreading

[Brooks Davis]

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

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Any statement of the form "X is the one, true Y" is FALSE.
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