AMD Socket-A 133MHz FSB/DDR Overclocking Guide

Two days ago AMD introduced the first DDR platform for the Athlon, the AMD 760 chipset.  The reaction to the introduction brought about mixed feelings, while some found the 10% improvement in performance to be nothing to write home about, others were more than pleased.  For those that weren’t overly impressed with the chipset, there’s something else about the chipset that may turn you on a bit more than you were initially.

Remember back to the days of the Celeron 300A?  The CPU, originally clocked at 300MHz (66MHz x 4.5) made the perfect overclocker as the core had no problem running at 450 – 500MHz.  However the Celeron was one of the first Intel CPUs to boast a multiplier lock, thus the only way to overclock the CPU was to use a higher FSB setting.  The official 100MHz FSB setting on the BX chipset was perfect as quite a few users bought this 300MHz chip and simply set their BX boards to 100MHz in order to have a “blazingly fast” 450MHz system that rivaled the performance of the most expensive Pentium IIs.  This is one of the best ways to overclock since you aren’t running the system bus nor the memory bus out of spec, which limits the only component being overclocked to your CPU, and if your CPU can handle it, then you’re in the clear.

Unfortunately FSB overclocking hasn’t been all too possible on the Athlon platform.  The AMD 750, VIA KX133 and KT133 chipsets all supported only one FSB frequency, that was the 100MHz setting that everyone ran at.  The chipsets weren’t designed to work with the 133MHz FSB setting and most of the time, motherboards based on these chipsets wouldn’t be able to go any higher than around 110MHz.  Luckily for the overclocking population, through the use of Gold Finger Devices like the Afterburner and the K7 Overclock card we were able to manipulate the clock multiplier of the Athlons.  Even the newest Athlons and Durons can have their multipliers adjusted through a very simple trick involving some of the “Bridges” on the CPU and with motherboards that support the multiplier adjustment features. 

But as we just alluded to, the AMD 760 chipset brings another overclocking possibility to Athlon and Duron users, the ability to use the 133MHz FSB.  Just like we could boost the Celeron 300A’s to 450MHz using the officially supported 100MHz FSB on most BX boards, the 133MHz FSB on AMD 760 boards will allow us to do the same to a handful of Athlons and Durons.

This guide will focus on some of the basics of Athlon overclocking since we haven't really devoted a full article to that yet, some warning signs to look out for when overclocking the Athlon/Duron, and finally the performance you can get from overclocking your Athlon/Duron using the 133MHz FSB on AMD 760 based boards.