I have a similar issue as this user. You can pretty much take his screen shot and apply it to my issue: Windows 8.1, 99% disk usage or in that vicinity for a longer period of time (minutes). Yet the individual disk usage stats don't add up to more than roughly 1MB/Sec. I have an SSD disk capable of much higher throughput.
The question I linked to doesn't provide much answer, but one comment hints to low free disk space. That is an issue with my disk. I have only ~1GB left of free space on my C drive. But my follow-up question is why would that matter? Windows does pre-allocate 6GB of virtual drive, doesn't it? At least that's how I interpret "currently allocated" in the Virtual Memory settings screen under System Properties → Performance options.
I've tried to use the process monitor tool to gain some information on what's using the disk, but the amount of data logged in just a couple of seconds is so vast that I don't know where to start. The only thing I see is that service.exe accesses the registry a lot... But I guess that's normal? If anyone care to take a look, the log dump is here (19MB)
- Does the disk usage really go up when free space declines? If so, why?
- Can anyone deduct from my Procmon log file what program or process causes 99% disk usage?
edit: To comment on the "malware"-answer in the other post: I'd like to know, not guess. I doubt it is malware in my case, but if it is, my logs should show that.
update: Similar case just happened. Any clues from these two ResMon screenshots?
"System" doesn't really tell me much.