[CentOS] CentOS 4.4 smp on Dual Quad Core Xeon

Mon Feb 26 17:32:38 UTC 2007
John R Pierce <pierce at hogranch.com>

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:

    # cat /proc/cpuinfo
    processor       : 0
    vendor_id       : GenuineIntel
    cpu family      : 15
    model           : 2
    model name      : Intel(R) Xeon(TM) CPU 2.80GHz
    stepping        : 7
    cpu MHz         : 2791.038
    cache size      : 512 KB
    physical id     : 0
    siblings        : 2
    runqueue        : 0
    fdiv_bug        : no
    hlt_bug         : no
    f00f_bug        : no
    coma_bug        : no
    fpu             : yes
    fpu_exception   : yes
    cpuid level     : 2
    wp              : yes
    flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr
                        pge mca cmov pat pse36 clflush dts acpi mmx
                        fxsr sse sse2 ss ht tm
    bogomips        : 5570.56

(repeat for processor 1,2,3)