GTS250s in SLI > One is 15C Hotter Than the Other

jedihobbitjedihobbit Central Virginia, USA New
edited April 2010 in Hardware
Have built my first SLI system over at http://icrontic.com/forum/showthread.php?t=88449 and noticed one of the cards in HWmon is running up to 15C hotter than the other, with Precision naming the hot one GPU1. The average is 13C by both utilities. This is with one card in the mid to low 50s and the other as high as 76C. This is while folding with the cards in SLI. When time and attitude come together I will knock out the SLI part.

Now is this a "normal" occurance for this kind of setup or should I figure out which card is #1 and redo the thermal goop? For those not wanting to go over to the log.....

I removed the hsf so as to paint the plastic covers. The first one I did actually ran 3 - 5 C cooler than "stock". I used zalman thermal paste (the one in the bottle) on both BTW. I did note that the second one in stock mode appeared to be running about 5C warmer but thought changing the thermal paste might fix that.

SLISideView.jpgSLIDetail.jpg

Comments

  • _k_k P-Town, Texas Icrontian
    edited April 2010
    You can always run one at a time to see if it is because of the extra heat from running dual cards or something didn't get put back together well enough.
  • shwaipshwaip bluffin' with my muffin Icrontian
    edited April 2010
    I'd guess it's because the top card is getting less airflow, and the airflow that it is getting is coming over the already hot bottom card.
  • Cliff_ForsterCliff_Forster Icrontian
    edited April 2010
    Hmmmmm

    So many potential factors, positioning in the case, air flow from other fans and compoenets, but a 15C difference seems pretty big.

    Have you given the thermal compound time to cure on each chip?
  • SerpSerp Texas Member
    edited April 2010
    In SLI the secondary card isn't fully used. Now in folding it might be different.

    I don't run SLI so I can't say if a 15c difference is unusual or not.
  • jedihobbitjedihobbit Central Virginia, USA New
    edited April 2010
    Think Cliff_Forester covered it pretty well in "So many potential factors", but the rest of ya are on the case!! :bigggrin:

    1. Still haven't confirmed it but believe the top card is number 1 (has cable)

    2. #1 is doing the lion's share of the work in SLI

    3. If you look at the second picture the 120 blows directly on the bottom card.

    4. A notoriously hot NB sits under under the top card.

    5. Old case equals only 1 x 80mm exit fan, need to work on something here as removing the the side panel dropped temps by 10C. :hair:

    And to "prove" that it is card position etc and not the an individual 250 I swapped the cards and still had the 15ishC temp difference.
  • _k_k P-Town, Texas Icrontian
    edited April 2010
    welcome to SLi
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