I read a lot about people having a big problem with MS 6553., I got some straight poop in an online chat with Compacq and heres the goodies..

it is a NV n force board upgradeble by downloading the updates from Compaq. Just have the Mod number of your computer..Download nforce updates to nforce2.

266 FSB

Will support and run correctly up to 2600+ Athalons with no bios change. Do not fool with the jumpers! Make sure your athalon is a 266 FSB as a 333 won't work..

I put a 2400+ with an ati 9600 Radeon Pro in, ran 10375 marks right out of the box, no oc no nothing except the new peocessor and the radeon., so the board isn't a mystery, just limited in what you can do..I am sure that it can be oc'ed and be a real monster..
AS usual, make sure you delete any other video drivers before pulling your old card so you have a clean install for the new drivers...
Iceman