"For Socket A processors like Athlon Thunderbird and Duron the process if a bit different. Since there is no PCB for the CPU there is no Goldfinger expansion port, however multiplier adjustments are available by connecting the L1 bridges together on the CPU. When connected these bridges allow electrical currant to flow to the 4 extra pins on the bottom of the Socket A CPU. A motherboard with multiplier adjustment capabilities is then required to allow multiplier manipulation. Unfortunately there aren't a great amount of boards out there with this feature at the moment but we have seen this feature take hold on a few companies with multiplier motherboard out now and other companies announcing board with the multiplier adjustments onboard. At the time of writing this review the only motherboard with multiplier adjustments either in BIOS or jumpered are; ABIT KT7 (RAID), MSI K7T Pro 2, EPOX EP-8KTA+, ASUS A7V and the ASUS A7 Pro."
FULL STORY @ TWEAKTOWN (http://www.tweaktown.com/articles/amd_overclocking/)