Constant stuttering/frame lag when in game.

my computer can hold decent frame rates (25-40 depending on the area) but it’s constantly stuttering/frame lagging every few seconds, no matter what settings I’m running.

It started after the update that initially introduced water reflections to the game. So I stopped playing around a month or two ago due to this reason, hoping that it would be fixed by now but nothing has changed.

I do have a fairly old low-end computer, and I do plan on upgrading within the next month or two. but my computer has always been able to play rust on medium settings with at least 30-40 frames.

So I guess my question is does anyone know what may be causing this?
Could this have something to do with the memory leak? or is it just my computer not being able to handle rust anymore?

Any feedback would be appreciated, thanks.

using dx9?

Yeah, the game crashes when joining a server on dx10