Registry entries aren't a perfect solution - they may not be updated during a system hang or crash (PrimoCache does invalidate L2 if it detects an abnormal Windows startup - but a system hang, as opposed to a BSOD, may not trigger that). And saying that avoiding offline modification is the user's responsibility doesn't stop it happening.lordsnipe wrote: ↑Fri Jan 15, 2021 8:50 pmI don't think that's the reason why it fetches from the HDD. Primocache uses registry entries to determine if the L2 contents are out of date and also says offline modification of files is a no no...InquiringMind wrote: ↑Fri Jan 15, 2021 3:22 pmIt could, but that relies on the L2 cache being current and correct (and there are a number of cases why this may not apply on system startup). Loading pre-fetch from the original data is the safest option and provides an extra opportunity for PrimoCache to check L2 (whether it actually does so is a question for Support).
So there is the possibilty of L2 cache being invalid without being detected, and that could lead to data corruption if it was used as the source for L1.
Directories/folders (and associated metadata) usage will typically not vary, and these can benefit from Prefetch (I use a snapshot-based install monitor - scanning an 850GB SSD volume usually takes 30 seconds but with pre-fetch it comes down to 10). Utilities like WinDirStat also show similar benefits.janusz521 wrote: ↑Sun Jan 17, 2021 12:24 pm Personally, I think that prefetch should not be set by default. It may be useful when someone is working with a specific set of applications all the time and wants them to run at full speed right after the boot. However quite often people work with different apps/games on every session so prefetch loads quite a lot of unneeded data that will be soon discarded. It may take some time too...
That's not to say that some data may be cached unnecessarily - but the overheads of discarding that data are minimal and the pre-fetch process itself seems to use idle time on startup (and takes about 20-30 seconds to complete from SSD in my case).