David C. Rankin composed on 2025-01-31 18:24 (UTC-0600):
Felix or others will have to speak to the Intel graphics limitations. It will use memory shared with the CPU, so you may be memory limited, or depending on resolution of "full-screen", processor limited to paint the entire screen.
Possibly RAM could play a part, and a change to BIOS settings to preallocate more RAM to graphics could help by using only contiguous RAM blocks. Perhaps it's time to run a memory tester as well. Some old RAM just doesn't last as long as one hopes or expects.
Just for completeness, on that old Dell, I've got:
$ inxi -G Graphics: Device-1: Intel 82G33/G31 Express Integrated Graphics driver: i915 v: kernel
G33/31 is Gen3 Intel. *965* is Gen4. Have you tried using his VMD whatever it is on yours?
Display: server: X.Org v: 21.1.15 driver: X: loaded: intel
The better supported modesetting driver is not supported by Gen3, forcing you to use the Intel DDX.