Should I install Windows and games on the same NVMe drive?

If you like keeping your game library separate for easier Windows reinstalls, you can create a second partition on the NVMe. Just be careful: reinstalling Windows or changing partitions can still erase data if the wrong partition is selected, so back up anything important first. A separate physical drive is generally safer and more convenient for that purpose.

Put Windows, drivers, applications, and games on the NVMe drive. It is easily fast enough to handle all of them at once, and separating the operating system from games usually provides no meaningful gaming benefit. The older 120GB SATA SSD is small and will be easier to fill up, which can also hurt its usefulness.

A separate partition can also keep games away from the Windows and Program Files folders, which may be convenient for heavily modded games. However, there is no performance requirement to do this. Installing everything on one large NVMe partition is the simplest option, as long as you leave some free space.

The NVMe may make Windows start and load applications a little faster, but storage speed usually has almost no noticeable effect on frame rates or 1% lows once a game is running. Stutters are more often caused by shader compilation, CPU or GPU limits, memory pressure, or the game itself. The main benefit will be faster game installation and loading screens.