Exact same issue here.
Ryzen 5 2600
Msi b450 gaming plus
Windows 10 21h1 (and win 11 beta)
Adata xpg m.2 nvme ssd (OS) (c:)
Samsung evo sata ssd (d:) (cache drive)
Wd black 1tb hdd (e:) (data/storage drive)
Getting the same symptoms of cpu0 running between 60-100% and "system interrupts" process hitting around 7% cpu usage constantly.
The main symptom which got me looking for a problem, was my dota 2 game dropping fps heavily down from 200fps to 40fps and stuttering constantly. Practically unplayable.
I found the storemi 159 version and installed it instead of the 191 version and the issue has gone.
We have addressed this issue on higher priority.
This issue was only observed in 184.108.40.206.
We will be providing fix for this in the next Storemi release, Mean while will update in this thread.
Thanks for your valuable comment... !!!!
Well... I'm back to the problems I had with version 220.127.116.11 (https://community.amd.com/t5/drivers-software/storemi-cache-offline/m-p/482162/).
18.104.22.168 has solved the high CPU, but for me it's back to "cache offline" after a while. The only difference is that version 22.214.171.124 was going offline at approx. 6.5% "space cache used", and now 126.96.36.199 has gone offline at 100%, but I think in both cases it means the SSD has filled up, and the different value is because the ratio, with the old version, was computed against the HDD (1GB), and the new version computes it against the SSD (64GB).