Computer will stutter and almost not load when playing games - recently new build.
Computer Specs:
Mobo: ASUS ROG Strix Z890-H Gaming WiFi Z890 LGA 1851 ATX Motherboard, Intel® Core™ Ultra Series 2 Ready, Advanced AI PC-Ready, 16+2+1+2 Stages, DDR5, 5Gb LAN, WiFi 7, 4X M.2, PCIe 5.0, USB Type-C®, AI OC
CPU: Intel Ultra 7 265K
RAM: 64 GB G.SKILL Ripjaws S5 Series DDR5 RAM (Intel XMP 3.0) 64GB (2x32GB) 6400MT/s CL32-39-39-102 1.40V Desktop Computer Memory U-DIMM - Matte Black (F5-6400J3239G32GX2-RS5K)
GFX Card: Geforce RTX 5080
M2 drives for storage
I can replicate the issue pretty frequently. All I need to do is login to old school runescape or D2:R and it will just completely make my computer render useless, I go from max frames to like 12 FPS in OSRS and can't even play the game (These games are never an issue regularly.) I thought I was getting messed with because every time I went to a boss, it would start and I would have to log out. Now, it also affects windows as well, Task manager takes forever to load (nothing is at 100% in fact everything is very low usage), explorer takes forever to load, (I have task bar set to hidden and when I hover my mouse at the bottom it will take a bit to appear.)
I have checked my temps, all is really good. As mention before, usage is like nothing for CPU/GPU in task manager. I did virus scans, nothing all clear. This randomly started happening a few days ago and I am not really sure what to resort to next as potential solution. What could be other avenues to look?