My apologies for my cut off email. As I was saying... there is an article at Tom's Hardware here: http://www.tomshardware.com/cpu/02q1/0203131/dual-02.html which details a bit about Hyperthreading, along with what it does and does not get you... 'cpu cache bound' (correct me if I'm wrong) is refering to applications that cause information to be stored in the L2 cache. http://www.webopedia.com/TERM/L/L2_cache.html http://www.cnet.com/Resources/Info/Glossary/Terms/l2cache.html I'm not sure what types of processes make heavy use of this cache but there performance is degraded by HyperThreading from what I understand. Basically if it ain't written for it, it will probably run worse rather than better. I have heard Hyperthreading referred to as a good idea, and as a hack. I tend to agree with 'hack' though I'm not an engineer and I can't really tell you with any degree of non-troll like intelligence. Jason ----- Original Message ----- From: "Robert L. Cochran" <cochranb@speakeasy.net> To: <psyche-list@redhat.com> Sent: Monday, October 14, 2002 8:35 PM Subject: Re: Hyper Threaded Pentium 4 > I'm new to the CPU-level stuff and don't have much background in them. > So some of the terms are new for me. Let me get really basic: why would > you want multiple processors on a motherboard as opposed to a single > fast processor? I take it that the Xeon line is for multiple CPU > motherboards -- you don't just run one Xeon, am I right? What does it > mean, to be 'cpu cache bound'? > > Do your comments also mean the Red Hat kernel won't need testing on the > new Hyper Threaded P4s? > > Thanks > > Bob Cochran > > Samuel Flory wrote: > > > Red Hat has support this since one of the 7.2 kernel updates. This is > > old hat on the current crop of Xeon (aka P4 Xeon). Linux treats them > > as multiple cpus. Don't assume that this will make your system faster. > > If you tend to only one process active at a time then it will slow > > things down. It's also really bad if you are cpu cache bound. > > > > > > > > > > > > -- > Psyche-list mailing list > Psyche-list@redhat.com > https://listman.redhat.com/mailman/listinfo/psyche-list > -- Psyche-list mailing list Psyche-list@redhat.com https://listman.redhat.com/mailman/listinfo/psyche-list
