Hi vcreation,
As correctly mentioned by you, mSATA SSD is used as cache for mechanical drives. Dell has not tested this system with a SSD as a primary drive for OS. The system might not be able to use the mSATA SSD to accelerate another SSD. However, you may follow the steps below to change the SATA Operation to AHCI in BIOS and leave the mSATA drive in the system and use it as a storage drive :
Note : The steps below might cause booting issues on system. You may refer to Microsoft article Here for making changes in registry before changing the SATA Operation.
- Power on the computer
- Press F2 when you see Dell logo to enter system setup
- Highlight Advance
- Change SATA Operation to AHCI
- Highlight Intel Rapid Start Technology and press Enter
- Disable iRST Support
- Press Esc and Highlight Exit
- Press Enter on Exit Saving Changes to save changes and exit
Hope this helps.