Using a program called siw.exe, I have determined that my southbridge is ich9r.

I don't see that listed under the options for installation though; here are the available ones (under System drivers):

SATA / IDE
-- Intel SATA
-- Intel AHCI SATA
-- JMicron
-- nForce SATA
-- VIAATA

Speedstep
-- Intel Speedstep a
-- Intel Speedstep b

Laptop Battery
ext2fs
NTFS-3G

Which of these represents an ich9r southbridge?