Adventures with 9800GX2 Folding!

LeonardoLeonardo Wake up and smell the glaciersEagle River, Alaska Icrontian
edited December 2008 in Folding@Home
For Christmas, granted, a bit early, I bought myself an Nvidia 9800GX2. I wanted to employ another computer in a dual-GPU Folding role, but the computer's motherboard, an Abit IP35-E has only one PCI-e slot. Well, why not a 9800GX2, I thought to myself. I started researching them and perceived them to be a good bang for the buck, if you could find the right seller. The card is essentially two 9800GTs sandwiched together, sharing a large frame, outer housing, and a single heatsink-fan.

Well, the card arrived USPS Priority, yesterday. I spent the afternoon reconfiguring the computer case for it, installing it, tweaking it, and LEARNING HOW TO COOL THE DARN THING.

If you haven't been exposed to a 9800GX2:
-they are h u g e! I installed mine in an Antec 900. There's just one inch between the end of the card and hard drive cage.
- they are hot! Smacking two video cards together does not allow for very good heat dissipation. At default clock, 600/1000/1500, with a GPU Folding client running on each core, one core was up to 90C at one point and the other ran at 84-86C.

The card's squirrel cage fan is at the end of the card, right next to the hard drive cage. The Antec's top front 120mm fan blows directly onto the intake, ensuring it sucks in plenty of cool air. So with running an unmodified GX2, this fresh air infusion is good! I've read at and a couple other places accounts of users having to underclock their 9800GX2s when Folding. Anyway, at 90*C, the card Folded on both cores successfully overnight.

Today I decided to strip off the factory thermal paste and apply premium paste. I figured that would be good for about a 10C improvement. I looked around the net for illustrations of disassembled GX2s. That was very helpful. It was very good for piece of mind to have a mental picture of what to expect. Long story short - 24 spring-tensioned screws, 9 standard screws, four itty-bitty SLI cables, a card mounted fan power cable, two outer shells, and two plastic card supports, and the 9800GX2 was disassembled. I took my precious time with the disassembly so as not to destroy some tiny component on the PCB that could spell doom for my latest hardware joy.

I performed the paste replacement on one GPU/card half at a time. This was the most complex thermal paste application I've ever performed, but I actually enjoyed the task. It was so different than any other chip-heatsink work I've done before.

OK, results: the application of quality thermal paste, Tuniq TX-2, knocked 18*C off the hottest core. Wow, I wish I could always get such fantastic results like that. So the card is now running relatively cool and performing like a champ. :rockon:

System 5 in my signature is the beast now containing the 9800GX2. What a performer it is, too. I currently have the GX2's shader clocks overclocked to 1664, up from the factory clock of 1500. I'll let it run couple days and then try a higher clock. In the same computer is a Q6600 overclocked to 3.5GHz. With two GPU2 clients and one SMP client cranking away...

12,000 points per day :hair:


  • _k_k P-Town, Texas Icrontian
    edited December 2008
    GG thats what mine does. Not to be a buzz kill though.
  • LeonardoLeonardo Wake up and smell the glaciers Eagle River, Alaska Icrontian
    edited December 2008
    GG thats what mine does. Not to be a buzz kill though.
    K, I don't know what you meant.

    Have you overclocked the shader clock? If so, what is the present clock, and how high above default is it? This card is an ECS - first of that brand anything I've owned. It seems to be very well made. The stock clock is 600/1000/1500.
  • mas0nmas0n howdy Icrontian
    edited December 2008
    K does the bulk of his folding on a single box: 2 x 8800GT + Q9450 = 12K PPD.

    Way to go on the temp drops Leo, just goes to show that it is always worth the effort of applying good paste. You'll probably avoid the overheat problems people are having running 2 of the new large WUs on the GX2.
  • LeonardoLeonardo Wake up and smell the glaciers Eagle River, Alaska Icrontian
    edited December 2008
    Not to be a buzz kill though.
    Oh, no, not at all, K. I was posting my remarks just to share an experience. I thought it remarkable what a PC with only a single video card slot can do, that's all.
  • lemonlimelemonlime Canada Member
    edited December 2008
    Very nice, Leo! 18 degrees.. WOW

    I know replacing thermal paste is probably one of the single best cooling upgrades you can make to a graphics card without replacing the stock cooler.
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