[Beowulf] Power draw of cluster nodes under heavy load

[Mark Hahn]

> Are any of you monitoring the power draw on your clusters? If so, can any of 
> you provide me with some statistics on your power draw under heavy load?

good question; it's something that deserves more attention and coverage.

ATM, I can only provide one non-answer:

http://www.sharcnet.ca/~hahn/saw-power-by-node.png

this is active mixed-user load (45 unrelated users, approximately 85%
CPU utilization due to memory scheduling and job layout constraints). 
this an older cluster, HP dual-socket E5440 (2.833G) whose IPMI happens to
return nice power measures.


> Ideally, I'm looking for the power load for a worst-case scenario, such as 
> running HPL, on a per-rack basis.

I don't understand the "per-rack" part - aren't you interested in per-node?


> I have some numbers from a friend who lurks on this list, but the more data 
> points I have, the better I can justify my power requirements for a new 
> cluster purchase I'm working on.

my experience is that vendors are useless in this regard: they always want
to quote the PSU max rating, and then often don't even use the number right.
(ie, put all the low-dissipation stuff like networking together, etc.)

has anyone tried to rate the accuracy of vendor power calculators?
at least a few years ago, they were absurdly inflated.

regards, mark hahn.