A look at the changed situation regarding power consumption

[Dresdenboy]

It looks like we have to reconsider CPU or system power usage of currently available CPUs because with the recent versions of Prime95 (24.11+) the increase of performance on A64 CPUs (LLR with some 15% or so and especially TF in 64bit mode with about twice the speed of 32bit mode) and the drop of Prescott's performance compared to Northwood changed the situation quite a bit. Prescott also consumes more power. So if people are concerned, they need some data. I'll try to collect them in this thread together with some accompanying calculations.

For a start:
http://www.lostcircuits.com/cpu/p4_840/20.shtml

This page shows the CPU power consumption of a mixed system lineup with Prime95 torture test running on these CPUs.

Of course we have to add the remaining system power consumption and include the PSU effectiveness into the calculation.

I'll try to make a complete table to inform about the commonly used configurations.

This thread will be a continuation of older threads, which covered this topic, like:
http://mersenneforum.org/showthread.php?t=3547
http://mersenneforum.org/showthread.php?t=3332
http://mersenneforum.org/showthread.php?t=2013

[Prime95]

It would be interesting to display in table format: CPU, CPU speed, CPU power consumed, LL speed for say 1792K FFT, kilowatts per LL test (for some arbitrary benchmark exponent like 33000000). From there it wouldn't be hard to calculate the 2 , 3, 4, or 5 year cost of ownership for a system as well as how much work it would produce in that timeframe.

Personally, I'm toying with getting an 820 or 830 Intel CPU but the power consumption is a bit scary. The Athlon dual-cores are too pricey. I'd like a dual core machine to tinker with development of multi-threaded FFTs. I'll probably wait a few months and see how things settle out.