I made a Windows 7 virtual machine. It defaulted to a SATA virtual hard disk. It's emulating an Intel controller and uses the Microsoft driver. Maybe the Intel driver has better performance?
Standard AHCI 1.0 Serial ATA Controller
Microsoft 6/21/2006 6.1.7600.16385
PCI\VEN_8086&DEV_2821
I have a Windows XP virtual machine which has Hard Disk 1 set to IDE. If I set it to SATA I get a warning that SATA is only supported for Vista or higher and that I would have to install drivers. The virtual machine uses a Boot Camp disk which already had AHCI SATA drivers for 8086/2680 but not for 8086/2821. Setting Hard Disk 1 to SATA causes a BSOD so I set it back to IDE and created Hard Disk 2 on SATA. I restarted and it shows new hardware and driver:
Inter(R) ICH8R/DH/DO SATA AHCI Controller
Intel 6/4/2009 8.9.0.1023
PCI\VEN_8086&DEV_2821
I shutdown the computer. Set Hard Disk 1 to SATA. Restarted. Still got a BSOD. This also happens when XP is on a virtual hdd instead of a Boot Camp disk. I can't install Windows XP to a SATA drive virtual .hdd either.
The Parallels SATA warning for XP always appears when I make changes to the virtual machine configuration even if I have drivers installed. It's very annoying.
A fresh install of Windows XP doesn't have the drivers so they need to be downloaded and installed. I downloaded and installed "Intel(R) Matrix Storage Manager" IATA89ENU.exe. "Intel(R) Rapid Storage Technology" iata96enu.exe is a newer version that works as well.
I can't figure out how to switch the startup disk from IDE to SATA without getting a BSOD. This might be similar to the problem reported at:
http://forum.parallels.com/showthread.php?t=104204