Re: Linux: more cores = less concurrency.

On 2011-04-11 22:39, James Cloos wrote:
>>>>>> "GA" == Glyn Astill<glynastill@yahoo.co.uk>  writes:
> GA>  I was hoping someone had seen this sort of behaviour before,
> GA>  and could offer some sort of explanation or advice.
>
> Jesper's reply is probably most on point as to the reason.
>
> I know that recent Opterons use some of their cache to better manage
> cache-coherency.  I presum recent Xeons do so, too, but perhaps yours
> are not recent enough for that?

Better cache-coherence also benefits, but it does nothing to
the fact that remote DRAM fetches is way more expensive
than local ones. (Hard numbers to get excact nowadays).

--
Jesper