John R Pierce wrote: > Morten Torstensen wrote: >> Tru Huynh wrote: >>> [tru at quadcore ~]$ uname -a >>> Linux quadcore 2.6.9-42.0.3.ELsmp #1 SMP Fri Oct 6 06:28:26 CDT 2006 >>> x86_64 x86_64 x86_64 GNU/Linux >>> [tru at quadcore ~]$ grep -A4 processor /proc/cpuinfo >>> processor : 0 >> >> Just take care with more than 8 CPUs, because you need the largesmp >> kernel then. Worked on a 8 socket, 16 CPU system where that was a >> pain due to binary kernel modules. >> >> Now those machines could be 32 CPU systems... and you could add 8 >> sockets more. 64 CPUs on Intel platform with commodity hardware. Not >> that many years ago that would have been utopia :) >> > > > I believe those quad core Xeon "Clovertown" CPUs support > hyperthreading too. which means 2 of them has 16 execution threads if > you've enabled hyperthreading in the BIOS. While many people > denigrate hyperthreading, we've got some Java > messaging/database/middleware stuff that gets a HUGE boost on a older > dual xeon* with HT enabled... this is with 2.8Ghz, 533Mhz FSB, 512K > cache Xeons of this flavor: No "Core based" CPU that I've seen so far (Pentium M, Core, Core 2, Xeon 51xx) can enable hyperthreading though they will have the ht flag show up in /proc/cpuinfo. The ht flag though was present in every Pentium 4 CPU, it is not a solid indicator that Hyperthreading can be turned on. Don't ask me why this is, ask Intel... Jay