Can you tell me more about the computer you built in 2009? How do you cool it? The motherboards look very close together. If they are number crunching I would think they would throw off a lot of heat.
yes, they throw off a lot of heat. actually, this started because i was running the heater in my apartment and thought, that's silly, i should get something more out of it.
i also found out that all the outlets in my apartment are on the same circuit. so i can't dry my hair any more :-)
actually, this cost a little more than i expected... last year i used 647kwh in february and this year i used 1124kwh.
i have considered other forms of cooling, but that can get expensive and messy. i have a process running that shows the internal cpu temperatures, and i have some margin, so i figure i am okay with fans for now. summer might be a problem...
i also considered overclocking, but i'd have to worry more about cooling and i'd only get 20-30%(?) and have to worry about incorrect answers.
Did you boot them to thumbdrives? Would it be better/easier to boot over the network?
yes, they boot off of thumb drives. i am running busybox and linux 2.6.28 from kernel.org.
it might be better to boot off the network, but i like the fact they are
independent. since they are networked anyway, i might change this.
Does each mobo have an individual power supply or did you figure out a better way to power them?
each board has a separate ps. i considered making cables to power two or more boards from the same ps (and i bought some parts), but i haven't got around to trying it. also, this creates a single point of failure and isn't much cheaper. it would probably not be much more efficient either.
What are the specs on the systems you assembled?
i'm mostly running q9650's at 3ghz. i built a spreadsheet that said this was the best power for the money. i haven't tried the new i7's because they are more expensive (mboard, mem, are also more expensive etc.). usually you pay more for stuff just because it is new, and i was looking for throughput/$. but it is hard to tell how fast your app will run without trying it. i'd be interested to know the ll cycle time for an i7.
since i am only running air cooling, i am not over clocking, but if i go for liquid cooling, i might. i thought about mineral oil, but that could be messy. also, you still need to get rid of the heat. the tenants on the floor below might not appreciate any leaks :-)
i'm actually pretty close to the limit of what i can do because of power. as i said before, all my outlets are on one breaker. i'd like to tap into the 50a circuit that powers my stove, but i don't know how to do it (or maybe it isn't such a good idea).