Question Loss of video after a few minutes of use.

[Eric Barney]

I have a new system that I just built with a substantial budget. and I am having major issues with the loss of video after the system is on for an undetermined time [it varies] The video becomes corrupted [noise/scrambled] and the computer becomes unusable. Things that I have tried to resolve the issue that did work temporarily: Ram modules swapped then replaced, different settings in the BIOS, etc. The system is not overclocked and XMP is not enabled.
Components list: Aorus Extreme X Z790, i9 149000k CPU, NZXT cooler 360, RTX4090 Gigabyte windforce VGA, 48gb PC8400 Gskill DDR5, 990 Pro 4gb M2.
I have never been able to enable XMP [won't boot] or run the 'Optimized' setting in the performance menu. Setting 'Spec Enhanced' had the system running for a while but the problem has returned and seems to be getting worse. There are no issues with temperatures since the cooling system is working well. This issue has been present from the very beginning. There are no BSOD's or any other indications by my various diagnostics that point to the culprit. The BIOS is up to date. My monitor is also responding as it should. Loss of video is from the source. The Intel CPU test passes in all areas, but the computer is running fine during the test.