1. I want the PC to boot from the RAID array, so I believe I must activate the RAID array via BIOS before installing the OS (which will be W7). Right?
Yes enable RAID in the BIOS and Ctrl + I to setup the Array.
2. When installing W7 (another "first" for me), will I need to do that "install an optional RAID driver" step that has been required in prior Windows versions?
No however you can load the newer drivers at the start or after W7 is installed.
3. I was planning to configure an array of two drives in 1+0 mode. I realize the performance would be better if I used 4 drives, but I have only two at present. The mobo manual says I need a minimum of 4 drives for 1+0, but I thought (from reading elsewhere) I could do it with only two. I've asked MSI about this, but since the controller is Intel I thought I might get a better answer here. So ... is it possible to configure only 2 drives in 1+0 mode?
No you are likely talking about the Matrix feature:
4. Would it be possible to set up a RAID 1 array now, using those 2 drives ... then later add 2 more drives and change the configuration to 1+0?
Going by the help file in 9.5 you can only change to a RAID 0 or 5 from a 2-disk RAID 1.
Change type from - To
2-disk recovery volume - 2-disk RAID 1
2-disk RAID 1 - 2-disk recovery volume
- - 2-disk RAID 0
- - 3, 4, 5 or 6-disk RAID 0
- - 3, 4, 5 or 6-disk RAID 5
2-disk RAID 0 - 3, 4, 5 or 6-disk RAID 5
3-disk RAID 0 - 4, 5 or 6-disk RAID 5
4-disk RAID 0 - 5 or 6-disk RAID 5
4-disk RAID 10 - 4, 5 or 6-disk RAID 5
I also have the GA-P55M-UD2 board. I can not get Windows 7 64-bit to get past the hard disk choice box. I have built a Raid-1 array in the BIOS, and have loaded the driver from the Gigabyte site (to get the latest). All I get is the 0x8030001 error no matter what I do. Ignoring the driver loading is not an option as the disk set doesn't appear there. I see from the above that there was no clear answer to the problem. Do you have any more that might help. Thanks.
I need to (and will) update this thread to show my original question was in fact answered. I was able to configure the RAID array in the BIOS and subsequently load W7 64 bit, without much difficulty. I hit an initial snag in the BIOS setup because I there were two RAID controllers listed (both disabled by default) and no clear indication of which was the JMICRON and which was Intel's. I wanted to enable the Intel but accidentally got the other one by mistake. So then I didn't see the choices I expected to choose the array type. But once I went back and enabled the right controller, the rest was smooth and easy. The RAID array was build by/in BIOS, then I installed W7 from disk. No problem.
The only kind of strange thing is that Windows 7 limited me to only two partitions (and I wanted to create 3). I'm not sure if this was somehow related to the underlying RAID array or what ... but it's not really a problem at this point, for me.
So ... this probably isn't any help to you, but that's the story. Good luck!