I got the Asus P5Q3 board today. After a couple of hours of hair pulling, I found out why I was not seeing the Intel Matrix Storage Manager or able to use the CTRL+I.
If you look at your main board, you will see there are 8 sata ports. I had my 2 drives incorrectly to ports SATA_E1 (WHITE) and SATA_E2 (PINK). These two ports are special ports for JMicron (not sure what that really is).
Here is a picture of the main board.http://www.asus.com.au/999/images/products/2563/2563_l.jpg
You do not want to use the bottom two sata ports, use the next level up from the bottom of the picture.
As soon as I moved my drive to ports SATA1 and SATA2 .... the intel matrix manager appeared! From there I had all the options RAID 0, 1, 5 etc.
Hope this helps and hope you do not have to re-install. But when a man wants raid, A MAN WANTS RAID!
Please post here if this helped.