I've been similarly surprised by how efficient modern boxes are. That said, boxes with a large number of CPUs can have a wide range of power requirements. We have some 64-core boxes that idle at ~150W but hit ~800W under high CPU load. I've found HPL to be a useful tool to get CPUs stressed out, but we're an HPC shop.
Skylar On Thu, Jan 16, 2014 at 6:16 AM, Edward Ned Harvey (lopser) < [email protected]> wrote: > In every server room, I always keep a spreadsheet showing how many VA > and W each UPS is rated for, and how many VA and W each system draws, and > which UPS's each server is connected to. It's a pain because I don't > blindly add up all the max power supply ratings (which are typically about > 5x higher than the *actual* max power requirements of the box)... In order > to get the measurement, I have to plug a power strip into a kill-a-watt, > and then plug both of the redundant power supplies of the box into the > power strip, then stress the system for a couple of minutes, and record the > measurements. This effectively solves a few problems (a) under sizing > UPS's, which I've seen bite other admins, whose data centers crash under > load etc, and (b) over sizing UPS's, which is what most admins do, and > wastes money and space, and creates unnecessary waste. > > > > Anyway, all that is just a tangent. Here's what I really came to say: > > > > Yesterday, I turned on a new server, took my power measurements, and was > blown away to find that the system drew a maximum of 110W and 120VA, > including 10% margin for error. Dang! They're getting good at power > reduction. Not long ago, I expected less powerful servers to draw 300-500 > or so, *actual* measured peak. > > > > BTW, assuming a typical server with nothing but cpu, ram, and disks in it, > the way I stress the system is to launch a zillion threads of "cat > /dev/urandom > /dev/null" and gzip, until "top" shows me I'm CPU starved... > I have found experimentally that stressing the disks and/or network and/or > other IO makes no noticeable difference to power consumption. If there > were any other power hungry components such as GPU, I would need to find a > way to stress that component as well. > > _______________________________________________ > Tech mailing list > [email protected] > https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech > This list provided by the League of Professional System Administrators > http://lopsa.org/ > >
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