I recently purchased a Acer Timeline M3 Ultra, it ships with a 500GB HDD and a 20GB mSSD to use as a cache.

First thing I did when I got it was format the drives and install a clean OS (on the HDD, the mSSD has nothing on it) - but now I can't figure out how everything needs to be configured in order to use the mSSD as a cache, it just looks like a standard storage drive.

I've poked around in the BIOS and there is a SATA mode setting, but it only has one option (AHCI), most of the documentation I've seen on the subject says that the SATA controller needs to be in RAID mode otherwise 'Acceleration' isn't visible in the Intel SRT menu (which for me, it isn't)

I've seen a few things that suggest I just need the correct partition layout, I tried this using fdisk from a Linux LiveCD but got nowhere.

Any ideas? The laptop shipped with no recovery media so I'm marginally stumped. I don't have any issue with reformatting again if required.