How is the extra mSATA SSD disk used/configured in a Dell XPS laptop?
Dell laptops with an mSATA SSD built in are in a RAID configuration enabling Intel's Smart Response tech to store a cache of the most used files on the SSD. This means faster boot times, application start times, etc. You can upgrade the built in mSATA to a bigger SSD, then go to the BIOS and change drive configuration to AHCI. You would have to re-install your OS but you can then install it on the SSD and use the hard disk as storage. This is my configuration and so far I have been happy with it with 4 second boot times to Windows 8. You really do not gain much if any battery life doing this, but the performance advantages in themselves are outstanding. I would caution that if you go this route, you should NOT install Intel's AHCI drivers as they are not compatible with the hard disk and would cause it to disappear for Windows (not the BIOS). Just use Microsoft's drivers and you'll be fine.
In the end I went ahead and bought the Dell XPS 15 so I'm now in a position to answer the question myself. The 32GB mSATA SSD is used to enable a range of Intel features - Rapid Start, Smart Response and Smart Connect - referred to collectively as Intel Responsiveness Technologies (PDF).
- No, nothing is installed on the SSD (at least, nothing the user can see or directly access). An Intel Rapid Storage application is installed on the regular HDD, accessible via a tray icon in Windows, which is used for enabling and monitoring Intel Responsiveness features.
- No, it doesn't appear as a lettered drive in Windows or at the command prompt.
- Too early to say. :)
The reference to booting "up to twice as fast" refers to Rapid Start, a proprietary hibernate-like feature which Intel claim is twice as fast as starting from a native Windows hibernate.