|oR|Spetsnaz
2[H]4U
- Joined
- Jul 20, 2004
- Messages
- 2,797
I am running SLI EVGA GTX 1080 FTW's and I have noticed that the temperature of the cards can sometimes be 20c different. I have a Corsiar 750D Airflow case (with the front mesh high airflow grille) and I have swapped the stock fans for 3 high airflow Fractal Design HF140 non-PWM models, which are 118 CFM compared to the stock fans which are 67CFM. My CPU cooler is a Corsair H110i GTX with stock fans and it is exhausting out the top of the case. The 1080's are in slots 1 and 4 of my ASUS X99A, so there is 1 slot of spacing between them. So basically, airflow inside the case should be pretty damn good.
Just so it's easier to visualize:
Intake:
2 x 140mm 118 CFM Front Fans behind mesh grille
Exhaust:
1 x 140mm 118 CFM Above cards
2 x 140mm 47 CFM on H110i GTX
When running Unigine Valley, you can see how GPU 1 (bottom) is running about 20c cooler than GPU 2 (top).
I can think of the possible scenarios being:
I feel like I am taking crazy pills here.
Just so it's easier to visualize:
Intake:
2 x 140mm 118 CFM Front Fans behind mesh grille
Exhaust:
1 x 140mm 118 CFM Above cards
2 x 140mm 47 CFM on H110i GTX
When running Unigine Valley, you can see how GPU 1 (bottom) is running about 20c cooler than GPU 2 (top).
I can think of the possible scenarios being:
- The bottom card is radiating heat towards the top card, athough 20c sounds like a pretty insane difference.
- Manufacturing variation in the GPU means it does not run as cool.
- The thermal interface material between the GPU and HSF on GPU 2 is flawed/not there at all.
- Airflow inside the case is not good enough.
![gpu 1.PNG gpu 1.PNG](https://cdn.hardforum.com/data/attachment-files/2016/08/thumb/64535_gpu_1.png)
![gpu 2.PNG gpu 2.PNG](https://cdn.hardforum.com/data/attachment-files/2016/08/thumb/64536_gpu_2.png)
![px gpu 1.png px gpu 1.png](https://cdn.hardforum.com/data/attachment-files/2016/08/thumb/64537_px_gpu_1.png)
![px gpu 2.png px gpu 2.png](https://cdn.hardforum.com/data/attachment-files/2016/08/thumb/64538_px_gpu_2.png)
I feel like I am taking crazy pills here.