[no subject]

If you run an SMP kernel and still only see one processor in /proc/cpuinfo
then either the Hyperthreading support is not turned on OR your processor
is not Hyperthread capable.

Now, as to whether it is a good thing or a bad thing to turn on, it is all
a question of the particular types of work loads the system sees. There are
cases where Hyperthreading is not actually a help and in some cases it may
actually be a performance degradation.

On Wed, Apr 14, 2004 at 10:40:40AM -0400, Dow Hurst wrote:
> Yes, I run two minimizations simultaneously on my single P4 and until the 
> second one starts the machine is very responsive.  It is truly like having a 
> dual CPU from my user perspective.  Run times are doubled on the minimizations.
> 
> 25m37.821s   Single run
> 
> 49m54.143s
> 44m10.795s   Dual runs (The second is the shorter due to different start 
> times, so this is general datapoints)
> 
> 
> These are GPCR receptor minimizations with delta 9 THC bound inside the 
> receptor.  About ~2700 atoms in vacuum using molecular mechanics and a lot of 
> torsional restraints applied.  Not a difficult calculation but is pure FPU on 
> C and Fortran code.  But, my point is the machine was acting like a dual CPU 
> machine in a very efficient manner.
> Dow
> 
> 
> Christopher Fowler wrote:
> > How is the performance? Is there a real gain?
> > 
> > On Wed, 2004-04-14 at 10:03, Jonathan Glass wrote:
> > 
> >>On Wed, 2004-04-14 at 10:02, Mike Millson wrote:
> >>
> >>>I have a box with a P4 processor running Slackware 9.1. What do I need
> >>>to do to enable hyperthreading support? Do I just have to compile a
> >>>kernel with SMP support? Are there any other kernel options or config
> >>>changes I need to make? Does anyone know of any good articles or howtos
> >>>on configuring linux for hyperthreading?
> >>>
> >>>Thank you,
> >>>Mike
> >>>

-- 
Steven A. DuChene     linux-clusters at mindspring.com
                      sduchene at mindspring.com


</pre>
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<li><strong><a name="00496" href="msg00496.html">[ale] Hyperthreading</a></strong>
<ul><li><em>From:</em> jonathan.glass at ibb.gatech.edu (Jonathan Glass)</li></ul></li>
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<li><strong><a name="00478" href="msg00478.html">[ale] Hyperthreading</a></strong>
<ul><li><em>From:</em> jonathan.glass at ibb.gatech.edu (Jonathan Glass)</li></ul></li>
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<li><strong><a name="00484" href="msg00484.html">[ale] Hyperthreading</a></strong>
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