Amithlon working fine on an Asus AN8-SLI mobo, 7800 GTX PCIe. AMD X2 4200+ CPU, 2 GB DDR - 4 x 512 MB. 500 watt Antec PSU.
SATA can be a bugger with Amithlon, but not having any issues with this combo with SATA hd's. 500 GB SATA HD, and an IDE CR-RW. SATA optical drives were a bit on and off, so just used the onboard IDE with no issues.
I have near the same parts in my FreeBSD pfSense machine, but the Asus AN8-SLI prmium board with a AMD X2 4800+ CPU and 4GB of ram, if your setup works mine should to (I think I have a 7800 GTX lying around somewhere).
So thanks, might merge my FreeBSD machine over to one of my LGA 775 boards laying around gathering dust instead! So I can give Amithlon a try (have never tried it)