On Thu, Mar 8, 2012 at 8:33 AM, m.roth@5-cent.us wrote:
VM's? Sorry, we're doing very serious scientific computing - the couple or so VMs we had are going away. I mean, when, for example, one guy I support gets on a 48 core box, and proceeds to fire up an R job, and uses*all* of them.... Plus, we're running out of UPSs to stick them on to, and sockets to reach....
ok, so 3 x 48/64 core servers uses the same power as 6 x 4/8 core ? thats still major win.
Um, no - that's what I'm saying is *not* the case. The new suckers drink power - using a UPS that I could hang, say, 6 Dell 1950's off of, *if* I'm lucky, I can put three of the new servers. And at that, if a big jobs running (they very much vary in how much power they draw, depending on usage), even with only three on, I've seen the leds run up to where they're blinking, indicating it's near overload, over 90% capability.
Yes, part of the power savings are deceptive - they only kick in when the CPUs are idle and your users would be one of the rare cases that peg them for long intervals. I think this is getting better in the current generation but haven't followed the latest changes.