switch to ahci mode before you install the new drive and then use the 16gb msata drive as additional storage or for your swap file (windows virtual memory). Personally I would use it for the swap file just to keep it off my new ssd and its small enough to actually make a good swap file drive.
I see. I'll switch to ahci before I install it then.
For page file/swap file drive, could you tell me how to do so? I didn't find too much info about that on the Internet (Please excuse my searching skill)
SanDisk SSD U100 16GB -> this is the mSATA I have.
Right now it doesn't show up so it's read-only I guess. Saw some articles saying that once I installed the SSD it will show up as I sign in as Admin.