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RE: spec2k comparison of gcc 4.1 and 4.2 on AMD K8


Nick, 

> I thought that L2 caches on the Opteron communicated by I 
> assume by your 
> response the  Opteron memory controller doesn't allow cache 
> propagation, 
> instead invalidates the cache entries read (assuming again the write 
> entries are handled differently).

You're half right.  The caches on the same processor do have a fast path between them, but the fact still remains that an L2 cache miss plus the cache coherency protocol overhead is far slower than an L2 cache hit.  Bottom line: process migration is bad.

HTH

-- 
_______________________________________________________
Evandro Menezes               AMD            Austin, TX




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