X-bit labs

How to Enable Additional 256KB of L2 Cache on AMD Athlon XP Processors Model 10.

Category: CPU

by Anton Shilov

[ 09/30/2003 | 05:18 PM ]

AMD Athlon XP processors Model 10 with 256KB of L2 cache appeared on the horizon sometimes after the launch of Barton in the first quarter of the year. The chips were based on the Barton design with disabled 256KB of L2 and a bit lowered speeds compared to the high-end AMD CPUs. Due to the fact that the devices essentially utilize “Barton” core, but have only 256KB of L2, just like the “Thoroughbred” microprocessors, the AMD Athlon XP Model 10 with 256KB of L2 are generally recognized under the “Thorton” CPUs.

From a number of previous experiences with AMD processors we know that disabled L2 cache or its parts may be easily enabled with a very simple modification, or a number of modifications. Frankly speaking, not just we, but the threat of all CPU and GPU companies – OverClockers.ru web-site! Yes, they did it once again and transformed the AMD Athlon XP processor based on “Thorton” core into fully functional AMD Athlon XP chip with 512KB of L2!

To get another “transformable” CPU from AMD you should find an AMD Athlon XP processor Model 10 with 256KB of L2 cache. You can distinguish them by a little bit “longer” core compared to ordinary AMD Athlon XP with 256KB L2 “Thoroughbred” chips. Such CPUs are often available among lower-end model numbers, such as 2000+, 2200+ or 2400+. Once you got such $60-$80 processor, lock up the L2 bridges, and, if you are lucky enough, you will get a fully functional Athlon XP “Barton” processor with 512KB of L2.

After you have done all modifications, be sure to test your processor’s and system’s stability in order to avoid glitches and lock-ups.

If you want to go further, try overclocking your microprocessor. If you chip does not boot up once you set another bus speed and/or CPU multiplier, boost its Vcore a bit (it should be about 1.75V) and try again. Our colleagues from the OverClockers.ru web-site have managed to get all their AMD Athlon XP “Thorton” modified into “Barton” processors running at above 2.20GHz core-clock; a nice speed for a $65 chip, isn’t it? But be sure you have a nice cooler for the beast…

Based on the facts mentioned here, we can again conclude that the yields of AMD Athlon XP processors with 512KB of L2 cache are relatively high at the moment since the vast majority of such CPUs are quite nice overclockers at speeds above 2.0 – 2.20GHz and all the microprocessors with half of L2 disabled are not only overclockable, but may be easily transformed into chips with 512KB of L2. This all means that AMD should have pretty normal profit margins on the current K7 CPUs and still has opportunities to cut the costs of such chips down.