SLI: One Card gets Higher Temps?

ProLeopard

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Feb 10, 2014
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Hello everyone,

I just got two brand new GTX 980 SOC graphics cards from GALAX.
The cards run great, especially when I had only one.

The card ran 1500MHz easily, with only a 12mV increase in voltage at about 78 degrees celsius.

Now, however, I have put in a new card and the temperatures have changed drastically.
The first card now runs at 80 degrees celsius, at stock speeds, not even overclocked.
However, the second card is chilling at around 60 degrees, easily able to hit the overclocks.

For airflow, I have two intakes at the front, one 140mm exhaust at the back, a PSU oriented fan-side up, and two Corsair SP120's on my H100i Radiator. The SP120's are intakes, people have advised me to switch them to exhaust so that the only intakes in my system are in the front.
Is this a good idea?

I do not know if this temperature difference is normal, as it is my first build and first SLI case, so I am not used to it.

Thank You,
ProLeopard
 
Solution
In SLI the top card typically gets warmer compared to the second one, it has less airflow available to it.

I would recommend 2 front intake, one back exhaust, and the H100i as exhaust at the top. This will give it linear airflow across the case.
In SLI the top card typically gets warmer compared to the second one, it has less airflow available to it.

I would recommend 2 front intake, one back exhaust, and the H100i as exhaust at the top. This will give it linear airflow across the case.
 
Solution


I see...
And one more question.
Why won't EVGA Precision let me overclock the bottom card and not overclock the top card?
I unlinked them and i set the overclocks, but neither cards get to the temperature I wanted...

Any ideas why?
I also tried on my friend's PC (He has the same exact setup)
and it wouldn't work there either.
 


That makes sense...

But after I told my bottom card to overclock with EVGA Precision X, it won't do it unless the top card also overclocks.
I unlinked the two and everything but it jsut stays at 1300MHz or whatever it is at stock.
 
Having dual cards running at full tilt does not mean the top card will always run hotter than the lower card, that is just a myth propagated by folk who don't know what they are talking about.

dualcards_zpsa1736ec0.jpg
 


The top card does run hotter most the time due to air flow and any time SLI isn't used. You can, on some motherboards, change which card is the primary card, and make it so the bottom card will be under load when SLI isn't used.

That isn't to say it's impossible to cool the top card, but under most setups, the top card runs hotter. Having a large space between cards helps a lot. Having good air flow also helps.
 


If I run a game with SLi enabled the temps of both cards stay the same as they are in that screen shot.
 


You do not have the only PC setup in the world. Most people see at least some difference in temps. Even the most well setup systems, usually see at least 2-5C different in temps on the top card. If there is no space between the cards, that difference is bigger. Some GPU coolers are more sensitive to a card below it as well. Some cases are more sensitive as well.

Just because your system does not have temp differences, does not mean most do not.
 


There is nothing special about either of my two PC's and yet with dual cards in both manage to run cards at pretty much the the same temp difference, and they both have different cases and fan setups.
 
Well, they are unique, if they see no difference. I believe you, but even in reviews, their is usually a few C difference. I have a unique setup though. I have one of those 90 tilted cases, so there is no top card, and I have 3 big fans blowing air up through my case with nothing blocking them. But if you only have 1 slot difference, the difference is larger than if you have 2. If you have no slots, the difference is big. Very big. Reference cards are less sensitive to having a card below them than the coolers that blow fan into the case.

Because of all the different possibilities, people have been saying "most", "typical", and similar verbiage. No one is saying all. Your 2 PC's do not represent most people. Nor does my Silverstone 90 tilted case.
 


Standard gap, nothing special or unique.

20141026_181449_zpsf149f073.jpg
 
i agree, if your sli setup runs at identical temps, then good for you. but the top card runner at a higher temp than the lower one is not a might, it's physics. esp those that are close together.
hot air goes up, not much space so hot air get's sucked by the top card. just my 2 cents
 
What likely is different with his, than most, is he probably has a fan blowing right into the center gap, which is not shown in the picture. While some systems have this fan, most don't, and even when they do, they aren't always positioned well. It's also possible that PSU is heating up the bottom card.

But the reality is, most people do have higher temps on the top card. Not all (I don't due to my case alignment), but most.
 


BINGO! That wasn't difficult to work out was it? And there is nothing to stop others from doing the same and enjoying having both cards run at the same temp.