I have seen many questions about running mobile Athlons on desktop systems.
I had to solve the same problem because I accidentally bought an Athlon
Mobile 2500 XP. So I could either return it, or figure out how to run it in
a desktop system. Here is what I discovered:



Most desktop BIOSes won't recognize the processor, although they run just
fine. However, the clock multiplier on the Mobile version runs differently.
My MSI motherboard was running this processor at 800mhz, using a multiplier
of 6 (133x6). This processor is made to run at 1.86ghz (14x133) with a
vcore of 1.4v. If your BIOS has a built in frequency adjuster, you're all
set. Just set the multiplier and you're good to go. I have 3 Athlon MBs in
house (MSI, DFI, and BioStar). Only the DFI had a multiplier adjustment
using a dip switch, but it only goes to 12.5.



I found a utility written by a Japanese student that works wonderfully. It
will let you change the multiplier and the vcore (if you can't via a
jumper). After making the adjustment, it allows you to create a shortcut on
the desktop with the adjustment. This just runs the utility in command line
mode. I verified the change using SiSoft Sandra, and it works to
perfection. I am now running the Mobile Athlon XP at 1.86Ghz with a vcore
of 1.4v. I have the processor fan turned down to about 1800rpm, so it is
almost silent. After running Sandra's processor benchmarks, the CPU never
got over 104F. That's very cool.



The utility is CrystalCPUID at http://crystalmark.info/?lang=en.



Hope this helps others.



RickB