Power Supply, CPU, And Cooler
Power Supply: PC Power & Cooling S75CF
It's a little ironic that the reason a PC Power & Cooling PSU wasn't ideal for our previous microATX build is precisely what makes it so attractive this time around. In our last SBM, we experienced less-than-ideal airflow out of our CPU cooler because the power supply didn't pull air from below.
This time, however, we're mounting the PSU below the motherboard, and since it only takes air in from the rear, we don't have to worry about it interfering with the lowest graphics card's airflow. In addition, the S75CF is CrossFire-ready with four PCIe power adapters, which are just enough to feed our quad-CrossFire Radeon HD 4850s. This is a great PSU for this application at $120.
CPU: AMD Phenom II X4 945
Usually, the CPU decision is foremost in our SBM articles, but this time around it was a bit of an afterthought, since the AMD theme was a foregone conclusion. With the graphics cards shaping the meat of the build, we simply picked the best CPU our budget could handle when the rest of the components were picked. In this case, that processor was AMD's Phenom II X4 945.
Sure, it doesn't have an unlocked multiplier like the 955 and 965, but we have the feeling it'll probably overclock almost as high, so it's a natural choice. And its current $170 price tag is agreeable (although we should add that prices have dropped a lot since we completed our build and the $190 Phenom II X4 955 is looking a lot more attractive).
CPU Cooler: Xigmatek Dark Knight S1283
The Xigmatek Dark Knight can dissipate a good amount of heat for the $37 price tag, which we’ll use to push the hot CPU and GPU heated air upwards and towards the NZXT Tempest case's upward-facing exhaust fans.