[Beowulf] power usage, Intel 5160 vs. AMD 2216

[Mark Hahn]

> The 2GB dimms emit the same heat as the 1 GB dimms.  So if you have a 1000 
> node cluster, and you use the larger (slightly more expensive) 2GB dimms vs 
> the 1GB dimms, you will emit somewhat less heat.  I haven't done the

assuming the same number of chips per dimm.  if your 1G are single-sided,
and 2G are double, you save nothing.  it's also interesting that for a given
generation chip, the higher-clocked dimms are significantly hotter
(say, 200 vs 300 mA max draw for 1G pc2/667 vs /800).

also, I notice that x16 chips dissipate a lot more than x4 or x8, even
though the chips have the same number of onchip banks.  I guess this says 
that the main power issue is driving wide parallel buses at speed...

> That and few parts means lower absolute number of failures, but that is 
> another issue.

a very interesting one.  I wonder how many people have scrubbing 
turned on in their cluster, and how many use mcelog to monitor the 
ECC rate.  comments?

thanks, mark.