Overheating SLI? Gtx780 ti

xander25

Distinguished
Jan 29, 2011
21
0
18,510
System specs:

I2500k
Egva gtx 780 ti
Evga gtx 780 ti classy in SLI

I've been noticing a severe drop in frames after playing fallout 4 for 30 minutes. I ran uningine benchmark ultra for 120fps but I noticed one 780ti was getting to 97C. Due to my board my SLI setup puts the cards pretty close together...am I running too hot?
 
Solution
When doing SLI, it's always advisable to choose a mobo which leaves 3 or more slots between the cards so as to leave you with some clean air space. Mounting a medium pressure fan (i.e Phanteks F120MP) on the back of the HD cage will usually eliminate the top cards +10C hotter temps.

My 780s are water cooled (EK full cover blocks) and run at 39C with fans all out and 44C w/ fans at an inaudible max 850 rpm.

The 780 Ti starts throttling at 85C so if you are hitting 97C, performance is being crippled.
https://www.techpowerup.com/reviews/MSI/GTX_780_Ti_Gaming/28.html

Temperatures are good and well below the 85°C limit beyond which NVIDIA's Boost 2.0 algorithm will start lowering clocks to keep the card cool. These results confirm...
When doing SLI, it's always advisable to choose a mobo which leaves 3 or more slots between the cards so as to leave you with some clean air space. Mounting a medium pressure fan (i.e Phanteks F120MP) on the back of the HD cage will usually eliminate the top cards +10C hotter temps.

My 780s are water cooled (EK full cover blocks) and run at 39C with fans all out and 44C w/ fans at an inaudible max 850 rpm.

The 780 Ti starts throttling at 85C so if you are hitting 97C, performance is being crippled.
https://www.techpowerup.com/reviews/MSI/GTX_780_Ti_Gaming/28.html

Temperatures are good and well below the 85°C limit beyond which NVIDIA's Boost 2.0 algorithm will start lowering clocks to keep the card cool. These results confirm that the MSI GTX 780 Ti Gaming is not only quiet, but also manages to do so without running at blazing temperatures.
 
Solution

xander25

Distinguished
Jan 29, 2011
21
0
18,510
I'm not over clocking.
The other tops at 68C
There's probably a quarter inch between my two cards...

I want to say it's a new issue....but I tend to mod my games and presume that performance loss is due to that so maybe it's not.

I'd probably do better with just the Classy and wait for the 1080, huh?
 

c4s2k3

Reputable
Sep 17, 2015
347
0
4,960


There may be some things you can try in the meantime. A couple more questions:

    ■ Do the cards have different types of coolers? You said 780ti + 780ti classy, so am I correct in thinking one is a reference design and the other (classy) is ACX (2 fans)?

    If so, you may get better results if you swap them on the motherboard. The reference design pulls in air from the case and expels out the back of the case. ACX pulls air from the case and expels back in the case. This could also make it worse depending on your case ventilation, but it might be worth a try. ** KEEP AN EYE ON THOSE TEMPS IF YOU TRY THIS. Use HWMonitor or something like that to check temps.
    ■ Is it possible for you to improve your case ventilation by adding a fan?
    ■ Try running a GPU utility like EVGA Precision X, and providing a more aggressive curve for the fan speeds. It will be noisier but if it keeps your temps from going critical, it may be worth it. If you game with headphones, you probably won't notice anyway.


Honestly, the case ventilation is probably your biggest issue. I happen to be running two dissimilar 780ti cards in SLI myself. One is reference design and the other is an ACX-style card. I don't play Fallout but I can tell you the temps on my hottest card does not go above 82 or so even after 2-3 hours of playing Battlefield 4 on Ultra settings on an ultra-wide 3440x1440 monitor.
 
Well SLI will always be the more economical way to extend system life another 18-24 months but it does require proper planning:

1. PSU must be sized accordingly.
2. Case cooling must account for the extra heat (add 1-3 case fans for extra card)
3. MoBo selection should take into account card spacing if air cooling.

Usually about this time (3-6 months before next series drops), you can find 1st tier older cards for great prices, many with water blocks as enthusiasts ready themselves for the "next big thing" (1080 or 1800).

I expect that the twin 780 Tis would still be faster in most games than a 1080 however the cost of adding the water blocks to those 780 Tis takes a lot of the shine off that option especially since, like the 9xx series, I don't expect to see any performance advantage from water cooling.