Ideas
22 days ago
It's not memory leak, but it seems Overkill graphics require more than 16GB of VRAM. You see, when there is not enough VRAM the graphics card tries to get some space for content from the RAM. Because RAM is much slower and farther from GPU than VRAM, you have FPS stutters.
Also dont look at VRAM values in the game, they're probably wrong. Use RTSS or FPS monitor and check your VRAM usage in real time.
EDIT: my graphics settings, with them I have no problems: