Opteron ECC

Peter Wemm peter at wemm.org
Sun Feb 22 21:47:14 PST 2004

On Sunday 22 February 2004 09:01 pm, James Van Artsdalen wrote:
> Several weeks ago I reported an instability in my system WRT ECC.
> It turns out that AMD has published its Opteron errata sheet and
> errate item 101 appears to be the issue: a bug in the Opteron means
> you can't have both "node interleave" and ECC scrubbing on at the
> same time.
> I've turned off node interleave.  I have no idea what are reasonable
> values for ECC scrubbing in ROM setup but it seems more useful to
> leave scrubbing on than to enable node interleave, even without a
> NUMA-aware kernel.
> (this only applies to multiprocessor systems)

Oh my, thats  bit of a stinker.  Do you recall which steppings this 
applies to?

BTW; I suspect you might find that node interleave is more useful (speed 
wise) than ecc background scrubbing.   But I guess that depends on what 
you want..  If you're trying to wring every bit of performance out of 
it, pick node interleave over scrubbing.  On the other hand, if you'd 
perfer to have the system constantly checking that the ECC ram is ok 
and you're not so worried about speed, then pick scrubbing. 

Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com
"All of this is for nothing if we don't go to the stars" - JMS/B5

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