Odd AHCI/RAID problem?

[Endymion FRS]

I have an old Acer desktop from 2009, and have been slowly building around it until everything is replaced, leaving only the drive it came with. It came with a 750GB Barracuda, split into two 341GB partitions (system and data) and the OEM partition. To completely replace it, I bought a 1TB Caviar Black. Currently, both are in an Asrock Z77 Extreme4. When I first put only the Acer drive in, I kept getting BSODs until I changed the bios to use RAID. Then when I put in the Caviar and put Windows on it, I needed to use AHCI. I need both drives to still have their OS, as two different people use them (I moved over to the Caviar) and I don't feel like hooking up a completely different computer when I wanted to switch. I figured I could just switch boot order and between AHCI and RAID when I reboot into mine or theirs, and was mostly right.

This is where the problem is. Rebooting from mine (AHCI Caviar) to theirs (RAID Acer) boots back into mine, POSTs, displays the "Windows is starting" screen for a split second, then reboots again to where I need to set the boot order to their drive for a second time, then it finally boots to theirs. When I boot back to mine by changing order to the Caviar and setting the BIOS to AHCI, I get the Windows start up error screen and have to select load Windows normally to get back to mine.

My questions are why does it do this, am I somehow hurting my drives by doing this, and why can't my motherboard set boot order properly the first time?

 

[Binky]

My guess: the new drive (caviar) is spinning up faster than the old drive. I'm not sure I fully understand your post, but there's an idea to think about.

You should use a hot swap bay if you want to swap between two drives. You wouldn't have this problem, and you'd be less likely to corrupt one or both of the drives.

 

[DigitalWolf]

You most likely were getting bsod with the 750gb drive because it was setup in IDE mode at some point. Its pretty common to get a bsod if you then try to boot up with the controller set to ahci.

You should be able to simply set the controller to ide mode and do what you want to do.


*edited for clarity and to add*


I mention IDE because it should work for what you want to do and is the absolute simplest method. You could go through the steps to get ahci working on the 750gb drive... which could be as simple as a few registry changes or could end up taking a reinstall with the controller in ahci mode. You could look up the benefits of ahci mode and decide what option you want to pursue. (ide or ahci).

 

[Endymion FRS]

You most likely were getting bsod with the 750gb drive because it was setup in IDE mode at some point. Its pretty common to get a bsod if you then try to boot up with the controller set to ahci.

You should be able to simply set the controller to ide mode and do what you want to do.


*edited for clarity and to add*


I mention IDE because it should work for what you want to do and is the absolute simplest method. You could go through the steps to get ahci working on the 750gb drive... which could be as simple as a few registry changes or could end up taking a reinstall with the controller in ahci mode. You could look up the benefits of ahci mode and decide what option you want to pursue. (ide or ahci).

The 750GB wouldn't work under IDE, I tried that when I first got the board and before I even messed with the 1TB. RAID was the only thing that would boot it up. How would I reinstall the controller on it, all it came with when I bought it was the Windows 7 upgrade disc? Sorry this is a strange and probably simple problem, I always thought hard drives were just plug in, switch, and go.