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The Cost of Distributed Client Computing?
ialbert asks: "I only recently decided to install SETI@home on my mostly idle home computer. It got me thinking though, are those free processor cycles truly free? Has anyone had experience with processors dying prematurely due to a constant, heavy load, or is usage pretty inconsequential? What about other components, like harddrives? And how much does a 100% processor load increase your power bill versus a 1-2% idle load over the course of a year? It's easy to think of idle computers as an untapped computational resource, but what are the costs to the computer owners?"
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People don't buy a Cray or Origin cluster to have the CPUs sitting at 1% load, they're made to work. If a home PC was properly cooled I'd hope that it should last to whatever the lifetime is spec'd at by the manufacturer.
Trolling is a art,
Since I figured the cost of the processor running at 100% was insignificant compared to the cost of the hard drive constantly spinning instead of spinning down during downtime, I created a small RAM drive on my various computers where I ran seti@home so that the file access wouldn't affect hard drive usage. This worked equally well on linux and windoze. The only other thing to do was to create startup and shutdown scripts to create the ram drive, copy the files over, and start the process and then to copy off the files before shutdown.
Why do I h8 apple?
My apc backups rs reports how much power is being used. When im at 100% cpu vs ~0% its an extra 17 watts.
For a 19" monitor + p3 + hard drives etc, its only about 220W total from the ups. (im sure much more peak from a cold start).
It's about 50-70 watts on the latest 3GHz PCs. An idling 3GHz Pentium 4 takes about 20 watts and a fully loaded one about 70-90 watts. At 15 cents the kilowatt-hour (that's what NYC pays), that comes out to an extra 21.6 cents/day or $79 per year compared to leaving the computer idle all year long.
So, yes, power is a substantial cost consideration. NYC power is also primarily gernerated with coal, so every joule of electricity used is that much more CO2 in the atmosphere. On the other hand, if the CPU cycles are going to a good cause, $79 is a quite affordable donation.
The power costs are negligible on a single machine. Run a farm and it can get expensive when you factor in cooling, which is the primary expense. Air conditioning running 24/7 or close to it in a house is far more costly than the consumption of a typical PC.
The advantage of the heavy CPU usage clients like GIMPs is the fact they are often the first things to detect an impending CPU failure. My GIMPs client running on an Athlon wound up saving the machine. I brought it up to see its progress and it was reporting hardware register mismatches. Turns out the heat sink fan had failed and the CPU was overheating. Fortunately, there was enough supplemental cooling in the case to keep the chip from frying outright but Windows was chugging along fine without any indication of a problem while GIMPs was saying "turn me off or die".
These programs exercise the CPUs to limits that few programs ever use. They make wonderful test and benchmark applications. When Cray tested their supercomputer CPUs, they used to do prime number calculations since any error in the floating point hardware would come out instantly.
Finaly a point where I have some numbers. I used to manage a net for a pharmaceutical company and we used to run the machines like most people. Turning them on when needing them and turning them off at night to save power. When we changed the SOP for computer use(on the teory that machines mainly die when turning on) to keeping the computers permanently on we had a decrease in service costs by 75%-80%. When these figures where held against the increase on the powerbill we saved ALOT of money (around 200 machines!!) When these figures where in we where given a pat on the back and a bunch of undrinkable flowers. When we also showed how much downtime we saved, we got a pat on the back an a full night on the town (with beer Free as in BEER ).
Doing it my way? All of them. And thanks to easynews, my pr0n DOES help society.