Xeon/P4 hyperthreading

[William Park]

On Tue, Oct 14, 2003 at 12:37:12PM -0400, Lennart Sorensen wrote:
> On Sun, Oct 12, 2003 at 04:18:40PM -0400, William Park wrote:
> > If there's anyone here with P4 or Xeon with hyperthreading and SMP
> > kernel, can you compile kernel
> >     make bzImage > /dev/null
> >     time make -j 3 bzImage > /dev/null
> >     time make bzImage > /dev/null		
> > and post the elapsed time for the last 2 commands.
> > 
> > Thanks.  It's time for upgrade, and I would like to get some feel for
> > hyperthreading in P4 and Xeon.  
> 
> I would love to do it, but I don't think the database users would
> appreciate it.  It probably wouldn't give the right results anyhow,
> given it has 4 xeon's in it.  As far as I can tell it looks as though it
> gives about 20 to 30% extra out of the cpu to have hyperthreading
> enabled.  On 2.6 it might be more (at least on multi cpu machines) since
> it has a better schedular that knows about related cpus.

Yeah, multi-cpu will skew the result.  The best is a single P4 or Xeon,
with and without hyperthreading.

I am also looking at AMD Opteron.  Nice, but decent motherboard is not
out yet.

-- 
William Park, Open Geometry Consulting, <opengeometry-FFYn/CNdgSA at public.gmane.org>
Linux solution for data management and processing. 
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