[Beowulf] Woodcrest Memory bandwidth

[Jason Holmes]

Joe Landman wrote:
>
> I have it on good authority that with the other chipset (we have a 
> Blackford here), we should see higher numbers.  Not exceeding the 
> Opteron 275 though.

We have both a greencreek based (the one with the snoop filter.. I guess 
they're calling it the 5000x now) and a blackford based system and I'm 
not seeing any difference beyond a percent or two of performance either 
in stream or in real applications.  Maybe we just haven't hit the magic 
app that greencreek helps yet.

> What I can say is that Woodcrest is interesting.  It just may be 
> overhyped by a "compliant" media.

I'd say it's a bit overhyped, but it is giving us some good real 
application numbers compared to the opterons.  On NAMD, Amber, and VASP 
so far, we've seen 2.66 GHz Woodcrest between 10-20% faster than our 2.4 
GHz dual-core Opterons while using all 4 processors in a box.  It's not 
the 50% media hype numbers, but it's definitely an improvement on the 
Intel side.

Thanks,

--
Jason Holmes