Graphics Card Performance Issues Relative to PCIE slots

[Kronos5959]

So recently I was having an issue with my GPU not performing as it should. It would lag frames in most games, and when I tried to stream, OBS was not able to fetch the frames because the GPU Copy function was not working at all.

I found a quick fix but now seek a resolution to the problem. The quick fix was to move it to my mobo's PCIE x8 slot and now it performs wonderfully as it should.

Hardware:

Asus Strix 1080Ti OC
Asus Maximus X Hero (Wifi A/C)

At first I thought is was a Windows issue, be it drivers or another OS-level bug. I tried DDU, turning off Windows 10 Game Mode, and wide variety of other questionable solutions. At the end of it all I ended up reinstalling Windows 10 from day one and running through each batch of updates to test the performance each time. After no solution there, I reset my BIOS and reinstalled each update Asus could provide.

That was the end of my troubles when I decided to swap hardware. I threw my 1080ti into an older computer I had buit and it performed as it should have. I subsequently tested the 1070 from the other PC in my current one, and sure enough it performed like a good looking potato. So I tried the PCIE x8 slot and sure enough my GPU was back on its way to solving the mysteries of the universe.

I guess the only question I have left is, did I miss something or do I simply have a bad mobo?

The rest of my hardware, if it helps:

8700k, delidded, 5.2GHz
16GB G.Skill Trident Z RGB @ 3400MHz
2x Samsung 960 EVO 500GB, RAID 0
Thermaltake Toughpower DPS G 1000W 80+ Titanium
CPU custom loop with EKWB parts

 

[DRagor]

It sure looks like a problem with PCIe slot. The only thing more you could try is changing PCie slot settings in BIOS (not sure what options this board has but certainly there are some). If that will not help solve the problem, I would consider motherboard faulty.

 

[Eximo]

Do you have any cause to suspect the motherboard?

Is it possible you did something to the CPU during delidding? Those slots go directly to the CPU.

Would be annoyingly difficult with a custom loop, but you might try re-seating the CPU in the socket.

 

[Kronos5959]

I have no cause to suspect problems with my motherboard, I take more steps than most people to take care of my parts adequately. My Mobo has an x16, x8, and x4 slot all at x16 length. The BIOS as I've explored cannot change up the bandwidth allocated to each of those slots.

I highly doubt delidding caused any issues with my CPU, I've also done experiments with a friend who also has an 8700k delidded, we've tested each chip on our boards to see which board is better for overclocking (he has a Gigabyte board of the same value as my Maximus) (my board is better lol), and the chip performs as expected on both mobos.

I have also since completely torn down the PC and rebuilt it with the same saddening results.