Sooo, kind of on topic:
What do you guys consider the best CPU for playing DF?
I guess that would be the i7-980x or the i7-975. 
Both can attain 3.6Ghz turbo frequency.
Ah, k, thanks. Is there anything besides the frequency of a single core that I should be paying attention to?
EDIT: JESUS CHRIST ALMIGHTY. Yeah. I'm looking for something AT LEAST four times cheaper.
Processor speed isn't as simple as it used to be, and unfortunately PC manufacturers aren't really doing a good job of informing people. Read the wiki on
Intel Turbo Boost, and then have a look at the numbers for different I7 processors
here.
Effectively, Intel has built on-demand variable overclocking into the processors. Many applications don't use more than a few cores effectively still; if the processor still has power and thermal headroom running only some cores, it will speed them up.
Good cooling is particularly important; a stock I7-870 has a rated clock speed of 2933 MHz, and Turbo binning of 2/2/4/5 (that's with 4/3/2/1 cores). If you're running only two of the cores, and have enough cooling to keep the thermal limiters happy, you'd be running 4 * 133 MHz faster, or a speed of 3465 MHz. Even using 3 or 4 cores, a well-cooled and powered system will run at 3199 MHz rather than the 2933 MHz performance you'd be getting on a cheap, minimum-spec motherboard with stock cooling.
This also means that for dual-core performance with good cooling, the less expensive chips are quite close to the top of the line. A comparatively inexpensive (about $280 retail) I7-860, well-cooled in 2-core-only Turbo mode, will run a nominal 3,333 MHz; an I7-975 Extreme (about $970 retail) only hits 3,466 MHz in 2-core mode, a bare one tick higher: a 4% performance increase for a 346% price increase! (Now, if you're running something like Matlab full-bore for a few days on all cores, the more expensive chip will do better, but that's not the usage profile of DF or in fact most users.)
The trick with a lot of these seem to be to limit use to two cores, not just DF but the whole system. I believe this is because if you're using half or less of the cores, it actually rotates which it's using; there's some switching overhead, but if you label the cores A, B, C, D it'll idle B and D while running A and C at full blast, until they get close to thermal limits, then flip to using B and D fully while idling A and C to let them cool down. If something kicks on in the background, though, the default scheduler will probably kick it onto a third core, which drops the Turbo allowed for the whole system. How to tune core affinities and priorities for something like DF is still unclear.
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Topic: How would DF handle a quad-core processor? (Read 4630 times)