I am already pushing the cooling limit of my rig with 3 x 6950 OC'd. There's an air gap between each card, a big-ass fan blowing directly on them, yada yada, yada...
I want more hashing power. The wife isn't going to let me start a new rig until this one starts producing, so...
I ordered some flexible PCIe 'risers' in order to add another card (or two), but I need to get the heat under control before I do anything. Here's my question:HOW DOES THE AIR FLOW THROUGH THESE CARDS? Does the fan pull IN from all the slots in the plastic shroud, and push OUT the opening in the back where the video connectors are? If so, why does 'blocking' the fan by putting the GPUs closer together have such a drastic impact on heat? Does the fan pull in air from it's 'hole' too?
A picture would be awesome!
Here's my plan: I have an old hot tub air blower (the thing that makes the bubbles) that I'd like to take advantage of. I tried using it to blow on the tops of the cards (instead of the big-ass room fan that's doing it now - side panel is removed), but temperatures went all over the place. Some up, some down... it was a mess. I shut it off and put the room fan back.
What I would like to do instead is rig up a shroud to place around the EXHAUSTS of the cards and use the blower to SUCK from there. And believe me - this thing'll suck a golf ball through a garden hose faster than a Thai hooker.
I'm willing to give it a shot (the bitminer - not the hooker), but need to verify where the exhausts really are. It seems like I can feel air coming out of some of the plastic vents on the GPU inside the case with my hand, but it's hard to tell with all those other fans blowing around.