hIOmon SSD Performance Monitor - Understanding desktop usage patterns.

[Anvil]

...
In any case, the reported maximum IOPS values reflect that which was actually observed by the hIOmon software based upon actual device usage - and not necessarily the maximum that the device (for example) can perform.
...

This is why I like the hIOmon software, it reports what is observed.

If I want to get the maximum iops I'd run iometer or sqlio for e.g. 10 seconds, that would give me the maximum iops.
For monitoring tasks that aren't synthetic one needs to pair several metrics in order to try to "fully" understand what took place.

As for the observations that may be "polluted" by cache, well, if the cache works it works for your benefit, cache is part of the system and it doesn't invalidate the result.