Would an SSD help with game stuttering, or just loading times?

It's a worthwhile upgrade, especially with Windows on the HDD too. Booting, opening programs and loading games should all feel much quicker. Games that stream assets as you move around may also hitch less.

That said, an SSD isn't a guaranteed fix for every stutter. CPU or GPU limits, memory pressure and other issues can cause hitches too. Think of smoother asset loading as a possible bonus, not a promise that every game will run flawlessly.

Before buying, check what the PC is doing when a hitch happens. If disk activity spikes and the game is loading a new area, the HDD is a plausible culprit. Also check CPU, GPU and memory usage. A busy disk alone doesn't prove it's causing the stutter, but it gives you somewhere to start.

NVMe isn't the only option. A SATA SSD is a big step up from a mechanical drive and may be a better fit if it's cheaper or your motherboard doesn't support an NVMe drive.

Check the motherboard specifications before ordering. An M.2 slot doesn't necessarily support every M.2 drive, and booting from an NVMe drive through a PCIe adapter depends on the system.

500GB is fine for Windows and a few games, but space can disappear fast with larger installs. Check the sizes of the games you want to keep on it before choosing. You can still use the HDD for other files and less demanding games.