So check this out....
I told y'all that I'm moving hardware over to both of my offices because I am going to lose the apartment where I've had two boxes folding along for the past year or so.
I got an ASUS P5N-D to recycle the Q9650 and move two 9800 GTs into. PCI slots are close together. Even though the cards are EE editions from Zotac (no external PCI-E plug), with stock cooling they were running in the 70's. Since the office they are in is now "Leed's Silver Certified" the AC is turned off at night. Made me a little uncomfortable, cause I'm sure the temps got over that overnight.
So, I bought another two Accelero S1's. I've got one on a regular 9800 GT (not the EE edition) and it's been folding nonstop at around 40 degrees passively. That's right. Passively, all the live long day.
OK, so on Wednesday night I installed those suckers. Did it the same way that I've always done it, even looked at the instructions to refresh my memory (this makes 5 that I've installed to date) and followed it to the letter. Tight fit in this board, but they will fit with millimeters to spare. No fans on the top card, of course.
Start folding. Temps start out in the 50's idle. IDLE. Crap, maybe stacked on on top of another is a bad thing, I dunno. Add a fan in front of the setup. One degree difference, maybe. Okay, what does it top out at? How about 95-99 degrees. WTF!?! It actually folds for a whole WU. I'm not kidding here. Tried everything, fans, case side off, etc. No real difference. Shit, I'm not gonna burn down the place for a few points so I turn off GPU clients for the night and go home.
Yesterday I thought about it some more, and took out the top card, disassembled it, and guess what. Less than 1/4 of the die made contact, and probably then because I had to angle it to get it free. The spacers are too big, so I took them off and just screwed the thing down by itself with no spacers. Bent the frame a little, but I didn't have an exacto knife or sandpaper or a file to whittle them down. Tested it, idle temps in the high 30-low 40 range. Folding full bore passively got to around 60 yesterday. No fan. Changed the other one, same story.
Two main thoughts here. If you are using the EE 9800GT editions or similar, be careful about die contact and the Accelero S1. Second, I can't believe that the card didn't die, and still folded a work unit at almost 100 degrees C. That's nuts.
Next step is to add a slim fan to the bottom cooler (12mm thick 120mm scythe or nexus or whatever) and see if I can lower the temps on both cards a little more. It's in a NSK4400B (I know, I know). Could get an Antec 300 for $50, but that's one more case with no place to put the old one.
Veni, Vidi, Complicavi