Originally Posted by Danzle
I agree that the NH-D15 is better, but depending on what i want to build (ATX SLI + 21:9, mITX Single+16:9) there would be some problems. The D15S would be a good choice for mITX (not the Impact i believe) but would be very high with a secondary fan if i chose fast (and tall) memory). The X61 or AiO for CPU in general was just the easter idea.
Edit: Just checked Noctuas charts and th NH-D15 should be compatible with the ROG M8I and judging by a test with the NH-D15 in a ROG M7I one could run both fans on "stock position" since one only has two DIMMs exactly between heatsink and fan.
For the GPU: It's hard to find a better 980Ti than the EVGA Hybrid.
For a mITX it might be a bit too much, but then again, I'd ask myself if I really need such huge cooling for an mITX build.
Regarding the GPU, you're just right, aftermarket or vendor-custom heatsinks can't compete even with a 120mm AIO (IIRC). I don't know if it's because of the fans, cooling area, or what. I do recall that the TR Shaman was a beast, but that was many years ago.