8GB VRAM should be fine (I’m using RTX3070 with 8GB VRAM myself), unless you are playing in a very high resolution. Would you post dxdiag dump of your PC configuration? Just press the win start key and type: dxdiag and in its window press “Save All Information” button.
Next, if you can, pls download Intel PresentMon → Download v2.1, install/start it and set Preset to “GPU FOCUS”.
Then play with it. It will show a special window with detail info about GPU utilization, temperatures etc.:
Could you make a screenshot and post it here?
If the bad perf (100ms frames would make it 10fps) is only occasional, it would need a video posted on youtube