[SOLVED] ASUS z490-e gaming: GPU runs @x8 on secondary PCI slot (NO SLI). It is normal?

[Maegirom]

Hi.
Since I have a large heatsink (Noctua NHD14), I can't use the first PCI slot on the motherboard and I have to use the second one. GPUz tells me it's running at x8.
The thing is that I thought the secondary slot would go to x8 ONLY if you were using SLI/Crossfire, but if you put a SINGLE gpu in the secondary slot it would work at x16.
I already know that the loss in performance barely touches 2%, just want to know if it could be a defective component. My complete gear is:

Intel i7 10700k|| ASUS rog strix z490-e gaming || 2x16Gb kingston hyperx fury rgb ddr4 3200mhz|| Noctua NH-D14 || Gigabyte GTX 1070 G1

I'm attaching a photo of the BIOS where it actually shows that in slot 2 I am working at x8. It gives me the option to switch to GEN 1, 2 or 3, but not x8 or x16. The only thing I want to know is if this is normal or if the motherboard/gpu could be faulty.
Thanks.

 

[KyaraM]

Depends on the MB. Many, if not most, only got the highest slot as x16 and every other at x8 or even just x4 in some cheaper ones. Usually, the metal strenghtened slot will be x16, the others lower. You will have to check the data sheet, but my guess is that that is how it is.

However, I ran a 1070 in that slot for quite a long time due to similar issues and it was only slightly slower, so it doesn't necessarily have to be a big issue. I think the difference was 5 FPS less on average. Really not a game breaker...

 

[DRagor]

Yes, it is normal. Back in the time when SLI was a thing we had more boards that would allow second slot to run x16. But now when SLI is dead it is no longer used and for most boards second slot is only wired x8.

 

[faalin]

How do you have the D14 installed? It should not be blocking the first X16 slot for the GPU.

 

[Maegirom]

Thanks for the replies!
@faalin Certainly I think I could place it in the first slot, but the plate would be almost in contact with the D14 fan. Don't know if that is a good idea. I have installed the D14 facing the airflow vertically from bottom to top. I have a HAF-X case with 2 big fans blowing air out at the top. Only one small fan at the rear side so this is the cause.
In fact it gives me very good temps actually. Right now typing this I have 27º+/- in all cpus. They barely reach 55ºC while gaming. And my GPU, I have never seen it above 69-70ºC (even with stress tests) , so I think it's a good airflow config.

Anyway, is there any problem about placing the gpu practically touching the D14 bottom fan? I guess it would be better leaving some free space, right?
Thanks!

 

[geofelt]

X8 would be normal.
Noctua shows the NH-D14 to be compatible with your motherboard:
https://ncc.noctua.at/motherboards/model/ASUS-ROG-STRIX-Z490-E-Gaming-3955

 

[DRagor]

but the plate would be almost in contact with the D14 fan. Don't know if that is a good idea. I have installed the D14 facing the airflow vertically from bottom to top.

In such setup going with GPU on first slot would probably increase your temps a lot.

 

[faalin]

Well sacrifices will need to be made, ether remount the D14 for a possible hotter cpu so fans blow from front to back of case and put your 1070 in the first slot. Or keep it the way it is and have a possible performance loss on the GPU

Quite frankly if your only getting 55*c on the cpu during gaming i would take the possibileity of a few degrees increase of CPU temps to get my GPU on x16 vs x8.......but thats just me.

 

[KyaraM]

Btw, does your case allow for a vertical GPU placement? With the necessary cable, you could place the GPU so that it blows against the side panel, but is connected to the x16 slot.

 

[geofelt]

X8 on secondary slots is normal.
X8 as a 2% issue would only be relevant tortx3080 class cards and higher.

Normally, the best orientation of an air cooler is to take in air from the front of the case and direct it to the rear of the case. Your front 230mm fan should provide all the airflow that you need.
The rear exhaust fan directs the airflow through the cooler and motherboard and out of the case quickly.
You might even shut off the top fans. They would tend to divert the airflow out the top before even reaching the cooler.

Do not worry much about the cooler being close to the graphics card backplate.
Touching will not likely cause a problem, but if it does touch, slip in a piece of paper or cardboard to keep them separated. Long time ago, I did just that with a NH-D15.

FWIW, the NH-D15s is designed with a slight offset to avoid just such a problem on some motherboards.

 

[DSzymborski]

Btw, does your case allow for a vertical GPU placement? With the necessary cable, you could place the GPU so that it blows against the side panel, but is connected to the x16 slot.

The viability of that is more than support; there are a lot of cases that support vertical GPU placement in a place that's quite awful. Remember, where you see the fans on a GPU is intake not exhaust; a typically mounted vertical GPU is drawing air from the side not blowing it against the side and sometimes, that's a real mess. Some Thermaltake cases are notorious for this.

Honestly, OP, the best thing to do is simply test it in both configurations.