Installing 2nd CPU on SMP board

[Chuck Swiger]

Glenn Dawson wrote:
> At 03:57 PM 10/19/2005, Kurt Buff wrote:
[ ... ]
>>> You want to get the same speed, FSB, and family number of Xeon, and  it
>>> is preferable to get the same stepping number if possible.
> 
> It's better to match the sSpec numbers...those include the stepping, and 
> not all processors of the same stepping have the same sSpec.

Intel's documentation for dual-proc and multiproc compatibility is based on 
family ID and stepping #, not on the s-spec #.

The family ID is akin to a major version number, and the stepping is akin to a 
minor version number.  You can get the family ID and stepping from dmesg, you 
cannot get the sSpec number via that directly.  For example:

CPU: Intel(R) Xeon(TM) CPU 3.00GHz (2992.71-MHz 686-class CPU)
   Origin = "GenuineIntel"  Id = 0xf43  Stepping = 3
Features=0xbfebfbff<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,HTT,TM,PBE>
   Hyperthreading: 2 logical CPUs

If you hunt down the right Xeon document:

http://download.intel.com/design/Xeon/specupdt/30240216.pdf

...and search for "0xf43", you get:

S-Spec CoreStepping CPUID CoreFreq FSB L2_cache ....
SL7ZF  N0           0F43h 3        800 2 MB     604-pin micro-PGA

-- 
-Chuck