T7920 Frequent disk access

My 7920 has developed an issue, or maybe I'm just noticing it. I'm hearing a sound about every second and seeing my drive light flash in unison with the sound.

I've used DiskMon from Sysinternals, to see what's going on, and it appears that it's the C drive being access, but it's unclear what's accessing it.

Now here's the strange part, I can hear it accessed every second, but the drive is an NVMe M.2 drive. What am I hearing?