CPU Fan and GPU Placement

Toggle sidebar Toggle sidebar
MeesterYellow

MeesterYellow

Honorable
Jan 12, 2017
563
0
11,160
Hello,

I'm wondering if I should move my GPU higher and if it's possible. My GPU is on the second PCI-Ex16 slot because the fan is huge. The manual and other forums say it's supposed to be on first slot for best performance.

Here are my specs: https://ca.pcpartpicker.com/b/9nnH99 - (pictures are there so it would be easier to help me) Be sure to 1+ me while you're there. Lol.
 
Solution
raisonjohn
Well, your motherboard (MSI X99A) does have its first two PCIe x16 slots configured to run at x16/x16 (*for 40x PCIe lane CPUs) or x16/x8 (**for 28x PCIe lane CPUs).

3 x PCIe 3.0 x16 slots (PCI_E1,3,5), support up to 3-way mode
- 1-way mode: x16/ x0/ x0
- 2-way mode: x16/ x16/ x0*, 16/ x8/ x0**
- 3-way mode: x8/ x16/ x8*, x8/ x8/ x8**

It's clear that since you have a 28x PCIe lane CPU (i7-6800K), plugging TWO GPUs at the first two slots (PCI_E1 and E3) would run it at x16/x8.

Now, what is not clear (and not specified in the manual) is plugging just a single GPU on that second slot (PCI_E3) would still run it at x16 speed (whichever CPU lanes you have) or defaults to x8.

But even if that second PCIe slot does x8. The performance...
Sort by date Sort by votes
geofelt

geofelt

Titan
Oct 9, 2006
54,307
4,149
174,240
Noctua redesigned its top cards with the s variant that are offset to clear graphics cards mounted in the first pcie slot.

The first pcie slot will by default run in fastest pcie x16 mode.
But on your X99 board, it would appear that you can run at X16 on two slots at X16 mode.

Even if you were to need to run at X8, you would see negligible performance difference.

If the card fits, go ahead and move it to the first slot.
If it is clear that there will be interference, keep it where it is and do not worry.
 
Upvote 0 Downvote
MeesterYellow

MeesterYellow

Honorable
Jan 12, 2017
563
0
11,160




Based on my pictures on PCPP, do you guys think there is enough space to move up?
 
Upvote 0 Downvote
raisonjohn

raisonjohn

Expert
Ambassador
Feb 22, 2015
4,102
91
39,040
Well, your motherboard (MSI X99A) does have its first two PCIe x16 slots configured to run at x16/x16 (*for 40x PCIe lane CPUs) or x16/x8 (**for 28x PCIe lane CPUs).

3 x PCIe 3.0 x16 slots (PCI_E1,3,5), support up to 3-way mode
- 1-way mode: x16/ x0/ x0
- 2-way mode: x16/ x16/ x0*, 16/ x8/ x0**
- 3-way mode: x8/ x16/ x8*, x8/ x8/ x8**

It's clear that since you have a 28x PCIe lane CPU (i7-6800K), plugging TWO GPUs at the first two slots (PCI_E1 and E3) would run it at x16/x8.

Now, what is not clear (and not specified in the manual) is plugging just a single GPU on that second slot (PCI_E3) would still run it at x16 speed (whichever CPU lanes you have) or defaults to x8.

But even if that second PCIe slot does x8. The performance difference would not be noticeable. You are looking at a 1 fps or even less difference in real-world graphs. See: https://www.youtube.com/watch?v=XJuj16gRoBI
 
Upvote 0 Downvote
Solution
MeesterYellow

MeesterYellow

Honorable
Jan 12, 2017
563
0
11,160




Still thinking about it moving it (might not because of hassle). Other than the unnoticeable difference in performance, are there any other improvements that could happen?

 
Upvote 0 Downvote
raisonjohn

raisonjohn

Expert
Ambassador
Feb 22, 2015
4,102
91
39,040


Aesthetically, you'll gain an improvement by being able to see those fans and red MSI design/LED glow directly (unlike now that you mostly see the backplate).

Spatially, you'll be creating more air space below the GPU for its fans to take in airflow coming from the front intake fans. However, you'll have more open expansion slots for that front intake airflow to escape at the back and the backplate won't be as much as exposed to the front intake fan's direct air flow. This is non-scientific observations though. So, for me, it might be a break-even scenario in improvements between having that GPU lower or higher. Short of saying it doesn't matter.
 
Upvote 0 Downvote
MeesterYellow

MeesterYellow

Honorable
Jan 12, 2017
563
0
11,160

Will there be more airflow based on my build? If not, then I'll probably keep it the same.
 
Upvote 0 Downvote
geofelt

geofelt

Titan
Oct 9, 2006
54,307
4,149
174,240


cooling is probably better where the gpu is now mounted.
 
Upvote 0 Downvote
raisonjohn

raisonjohn

Expert
Ambassador
Feb 22, 2015
4,102
91
39,040
Volume of air collected at the bottom of that GPU is higher because there's no open expansion slot for the air coming from the intake fans to escape at the back. (again, not scientific but only visual/physical observations).

I'd keep your setup as it is.
 
Upvote 0 Downvote
MeesterYellow

MeesterYellow

Honorable
Jan 12, 2017
563
0
11,160

Alright, will do. Be sure to +1 my build. I've done it for yours. I'll do it for anyone else who has PCPP, just provide the links and make sure you +1 mine. Thanks.
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom