Question which GPU do i switch to for my monitor?

Sep 19, 2021
I've just built my first pc and everything is working well EXCEPT my monitor has these fuzzy lines going across the screen diagonally. My best guess (I'm still new at this) is the graphics card cant keep up with the pixel demand.
I've updated all the drivers (multiple times) done factory resets, even removed and reset the physical card, and no difference. (as well as the memory)
2 things of note; 1. the pc works perfect on my tv (4k, 30hz) 2. during the install process for the driver(s) the lines go away UNTIL I obey the prompt to restart the computer, then the lines return.
I've tried to look up this problem specifically and have had no luck. My best guess, is I need a newer/more powerful GPU. I'd appreciate any input at this point. (i.e. which GPU is the least powerful that would still give work perfect, considering other parts to replace, trying to fix software before going through the hardware, etc.)

AMD Ryzen7 3700 3.6 GHz 8-core CPU
Deepcool assassin III 90.37 CFM CPU cooler
MSI MAG B550M mortar Wi-Fi micro ATX AM4 motherboard
G. skill Aegis 8 GB (1x8GB) DDR4 3000 CL16 memory (two of them)
Deepcool DA-N 600 W 80+ Bronze certified ATX PSU
Radeon RX 570 GPU
ASUS TUF Gaming 32" WQHD (2560 x 1440), 165Hz HDMI

"the graphics card cant keep up with the pixel demand"
Oh you poor sweet summer child. No, that's not it. That GPU is more than capable of handling that 1440p monitor at 165Hz. Your issue can either be one of the following:
  • Your Monitor is bad
    • Test method: You can test this by simply plugging in a laptop/other PC or console to it and see if the monitor runs normally. Rule out this option.
  • HDMI cord is bad. (best case scenario but least likely)
    • Test method: Simply try a new cable
  • Your GPU is bad, which seems like the most likely case since those diagonal lines are called artifacts and that usually happens when the card's VRAM is overheating OR the card itself has an issue to the manufacture level, in other words unrepairable by normal means. (worst case scenario).
    • Test method: Check your card's VRAM temps first using GPU-Z and see if you're memory temps are hitting the max while sitting idle (if it's 90C or higher then that's dangerously high for idle usage). If the temps are high you may need to take apart your card and see if there's any missing thermal pads covering the VRAM chips or just not making proper contact. Hopefully that's the case and you can fix the issue yourself. If not, you will have to replace that GPU.