First of all, double check that your video cable is plugged in snugly and doesn't have any damaged pins or contacts.
For the sake of troubleshooting, can you turn your system off for a total of at least fifteen minutes before booting it back up again?
NVIDIA drivers have been known to cause issues in the 4x and 5x series GPUs that may cause permanent damage and overheating.
If after booting your system up after a long rest
it doesn't exhibit any artifacting then it may be an overheating issue, in which case I would prompt you to:
- Remove your current drivers by using the NVIDIA Driver Removal Tool or Driver Sweeper available freely from Guru3D or upon a Google search.
- As per usual you can find the latest NVIDIA drivers to install afterward.
Please monitor the temperature of your GPUs for anything inconsistent or obscure after performing this.
I would suggest checking your GPU on the motherboard — ensuring that it is locked in tight and there is nothing between it and the contacts inside the motherboard.
You should not be experiencing any artifacting during the boot process.