The top fan blows downwards over the base of the heatsink and mosfets, the fan on the GPU blows towards the back of the case, the rear fan sucks the air out, those two fans on top blow cool air into the case.. all that really doesn't matter cause the side panel is usually off, hah
That's an EVGA E760 A1, rev 1.0 with a Westmere mod
Oh! Here is the NB heatsink with the CPU Heatsink. With it orientated vertically (air flow from front to back) it just about doesn't fit
Ah...thanks for the images. Now my head really hurts. ;-)
Poor little Megahalems trying to run semi-passive. Boxed in on all sides. Intake airflow from the barely-touching-the-sink top fan into the cooler gets smushed into that thermal blockade, er, NB sink already pre-heated by the GPU and chokes the flow. The angled mid-case fan is kinda pushing the heated air back into the cooler on its convoluted way to the rear exhaust fan.
How many GPUs are installed?
Getting a waterblock on that Xeon is probably the best solution.
An offset high-compatibility cooler like the D15S/TS 140A/IB-E would be good too. Would need to confirm the space from the center of the socket to the edge of the thermal blockade sink. If it's 67mm or more the D15S will fit in the proper front-to-back layout.
Alternatively, a few minutes alone with that NB sink and a large hammer would be the most satisfying.
If X58 boards weren't so scarce, I'd opt for the latter. ;-)
Or...replace that sink with a more reasonable one. Or put it under water. The NB sink on my Sabertooth is small(ish), low and out of the way - with a 92mm GT on them, temps are in the mid 40s.
Impressive how that combo manages to make that big case look so cramped. What an awesome challenge!
Would love to be there with you to tweak into total coolness. But, you probably wouldn't want my help and my little airflow helper, Mr. Ballpeen. ;-)