Just got build 10041
This is the first build of then that lets me install readycache software.
It does start with 0.07 used and increase the amount used as I read from the HDD.
It does make booting faster after three reboots and seems to work up to a point.
If I let the PC sit unused for an hour or two, then the cache goes back to 0.07 used and the system is very slow untill the cache fills up again. This has happened about once a day since I got it running on 10. Sort of sounds like win 10 might be directly accessing the HDD during some maintenance or update that is performed when the system is idle.
Any help or news from Sandisk would be warmly welcomed.