So today I tried to install Fedora 8 on a SATA drive, connected to one of the on-board SATA ports of an Asus A8V-VM motherboard. Fedora installer would consistently hang for several minutes at the "Loading AHCI driver" screen, then fail to find any hard drives to install on. This was quite puzzling, since I'd installed Fedora Core 6 on this motherboard previously without incident.
After much head-scratching, flashing the BIOS to the latest version (this had no effect), and Googling around, I finally got it sorted. Turns out newer Linux kernels enable something called MSI (Message Signaled Interrupts) by default. Apparently this is a new(ish) way for PCI and PCIe devices to signal interrupts to the CPU, which supposedly does away with the concept of IRQ lines.
The problem is, MSI is broken. I'm not sure if the problem is with the kernel itself, the MSI implementation on this motherboard (it has a VIA 8251 southbridge, so hardware bugs would not be surprising), or a combination of the two. But apparently other people have been having similar problems ever since MSI was enabled by default in the Linux kernel a few months back.
So anyhow, adding pci=nomsi to the boot options fixed the problem. Just thought I'd share that, in case anyone else has been trying to install a new(ish) Linux distro on a SATA drive, and is having similar issues.
If the world isn't making sense to you, you're either drinking too much or not drinking enough.