On Mon, 2009-12-07 at 22:16 +0200, Jussi Lehtola wrote: > 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. Well the Intel ads make XEON hyper-threading sound like the greatest thing since sliced bread, > -- ======================================================================= It would be illogical to kill without reason. -- Spock, "Journey to Babel", stardate 3842.4 ======================================================================= Aaron Konstam telephone: (210) 656-0355 e-mail: akonstam@xxxxxxxxxxxxx -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
