I just moved to an apartment that seems to have two heat settings: Arctic Circle and Dante's Inferno. The room I'm using as an office/den gets warm sometimes as a result; a problem for someone running a hot i7.
I'm currently using an ATCS 840 in it's factory configuration along with a Megahalems/1900RPM generic 120x25mm fan. With that setup things were getting a little hot for my liking especially with the warm ambient. CPU temps under Small FFT crested just over 80*C and GPUs were getting into the 70's running WoW (although the fans didn't spin up from their resting 40% either).
This time around I thought I'd side-step my anal retentive nature and skip past pouring over reviews; trying to find that perfect balance between cost, sound, and performance in a fan. I headed straight to Micro Center and picked up three 120x38mm Ultra Kazes in 2000RPM flavor. I also had a handful of 1200RPM SlipStreams <waits for boos to quiet> laying around so I thought I'd implement those too.
STEP 1: Remove the two 75CFM, 230mm fans from the roof and use the supplied bracket to mount three 101CFM
Source 120mm fans in their place.
STEP 2: Add two SlipStreams to the bracket on the backside of the HDD cage
STEP 3: Turn the rear exhaust fan around to become an intake. Replace with SlipStream
STEP 4: Mount fan on opposite side of Mega as to pull air from the newly-flipped rear fan.
STEP 5: Implement the admittedly ugly rear-GPU-box that CM supplies with the 840.
RESULT:
CPU (hottest core)
Before: 81*C
After: 71*C
GPU
Before: 73*C
After: 55*C
Ten degrees on the upper end of the spectrum of an i7 is nothing to scoff at. That's a significant amount of additional heat being wicked away. Sure the system is loud as hell now but until the funds become available to allocate some water-cooling it will have to do. Next I will fit some respectable fans on the Mega...
EDIT: Also, beforehand where the GPUs during FurMark would not reach equilibrium even with fans running 100% and temps soaring into the 80's they now plateau in the low 80's running 70% and 55% duty-cycle respectively.