Re: To hyper-thread or not to hyper-thread

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Mon, 2009-12-07 at 09:44 -0700, Greg Woods wrote:
> On Mon, 2009-12-07 at 16:18 +0100, Joerg Bergmann wrote:
> > The problem of the Pentium 4 D: It is not really a dual core one.
> > Hyper-Threading means: There is one core with two execution paths, which
> > means some of the common CPU features, but not all, are present twice.
> 
> One feature in particular that is not present twice is some of the
> caching. This is sort of why they named it "hyperthreading". If you can
> get multiple threads of the same process, sharing the same memory, to
> run simultaneously, there is a performance boost. But if you try to run
> two completely different processes simultaneously, there will actually
> be a performance LOSS because of all the cache misses this will cause.

This may not be true - in the high performance computing community
hyperthreading is usually not used, since if you're cpu bound, then
execution is about 20% faster in without hyperthreading since no
performance is lost because of the dual core emulation.

However, in normal desktop use you don't really care about the MFLOPS;
hyperthreading makes the system more responsive.

-- 
Jussi Lehtola
Fedora Project Contributor
jussilehtola@xxxxxxxxxxxxxxxxx

-- 
fedora-list mailing list
fedora-list@xxxxxxxxxx
To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list
Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines

[Index of Archives]     [Current Fedora Users]     [Fedora Desktop]     [Fedora SELinux]     [Yosemite News]     [Yosemite Photos]     [KDE Users]     [Fedora Tools]     [Fedora Docs]

  Powered by Linux