Hi there,
I'm using the same chipset on the GA-990FXA-UD5 for running a RAID0 Array but I have mine configured slightly differently, insofar as I have my OS installed on the RAID rather than on a separate drive and I have drives attached to all of the AMD SATA ports.
You might like to read through this thread:
http://forum.giga-byte.co.uk/index.php/topic,5704.msg45816.html#msg45816 where I go through setting up a RAID0 Array on the AMD Chipset as it may give you some ideas.
If I were putting together your system I would start over and do the following:
Remove all of the drives from the system except for the one drive that you want to install the OS onto and the DVD/CD burner.
Attach the OS drive to the 1st AMD SATA3 port and the DVD/CD Drive to the 1st Marvell SATA Port
In BIOS set the AMD SATA Controller to RAID and the SATA Ports 4/5 to "As SATA Type. Set the Marvell GSATA Controller to IDE
Install the OS - You will need to install the AMD RAID Drivers via F6 during the Windows Installation and can do this from either a USB pendrive or from the installation disk that comes with the motherboard.
Once you have installed the OS and loaded the basic drivers for your system shut-down the PC and then attach the 2 drives for the RAID Array
Start up the PC and press the "Ctrl + F" keys at the AMD AHCI check screen to enter the raid set up.
Configure the RAID0 Array
Restart the PC.
Hopefully doing this will solve the problem for you.