Lack of available PCIE Lanes affecting GPU

Kronos5959

Commendable
Aug 10, 2016
30
0
1,540
Hello all,

I am currently having an issue with my gpu in the 16x slot on my mobo - it doesn't perform well at all, in fact worse than in the 8x slot. Canada Computers has tested my board with multiple cards, processors, and a fresh install of Windows and were unable to replicate my issue.

My question is, can a large amount of usb devices, along with three storage devices, use up too many pcie lanes for the gpu to perform as intended?

PC COMPONENTS
Asus Maximus X Hero
Intel Core i7 8700k
Asus ROG Strix 1080Ti OC
16GB G.Skill Trident Z RGB
2x Samsung 960 Evo 500GB M.2
WD Blue 1TB
2x Thermaltake RGB Fan Controller (connected to usb headers)

USB DEVICES
1 keyboard
2 mice
Joystick
Xbox Controller
USB Audio Interface
3D Printer Data Cable
 
USB devices don't use PCIe lanes. There are hard coded lanes that run from the MCH (Or whatever Intel calls the Southbridge these days.) to the CPU. Doesn't matter how much you plug in there, it's the same amount of lanes.

How do you know it performs worse? What measurements have you took?
 

Kronos5959

Commendable
Aug 10, 2016
30
0
1,540


I've reinstalled windows, tested my cpu and gpu on other boards with no issues but the difference in the other systems was the storage device setups and usb devices connected, as well as monitors. I've tested a large variety of games by performance, from Minecraft all the way to games the likes of ACO and GTAV, all which perform great on my 8x slot but terribly on my 16x slot - ex Minecraft would run at 25fps on my 16x slot vs 300+ on my 8x slot. This is how I know it is a motherboard issue and not a gpu or cpu issue


 
My first guess is any chance you have the 8x and 16x backwards? Perhaps what you think is the 8x is really the 16x? My next guess is the 16X isn't running at 16x due to damage or dust, etc. I would argue there is nothing wrong with the system if the 8x slot runs things fine.
 

Kronos5959

Commendable
Aug 10, 2016
30
0
1,540


The top pcie slot on the Max X hero is 16x. I've inspected for damage on both the board and the gpu with a magnifier/microscope, as has Canada Computers (we actually have a great technician), but alas no damage found. I would argue my board and the rest of my system is fine as well, yet the issue persists through every possible solution. My last check is this post, making sure my PCIE Lanes are not jammed.

 

Kronos5959

Commendable
Aug 10, 2016
30
0
1,540
it indicates the bandwidth at 484gb/s and 242gb/s in the correct slots, clock speeds are normal, the card doesn't switch p states cause it rips through everything without getting too hot to throttle