I'm assuming its the 2800XP, as I don't think the board supports the 333
fsb chips. Or does it? I'm getting conflicting info off the web. Thanks.
KT400 can support 333 fsb CPU,
http://www.via.com.tw/en/apollo/kt400.jsp
Whether your particular motherboard has "official" support or not
is another matter. You failed to mention that board make/model
so check the manufacturer's bios notes, consider updating the
bios with current/old CPU in it... Odds are you can run any 333
fsb chip, and "maybe" even a slightly o'c bus for a 400 fsb chip.
That is even without the updated bios but it could be useful to
do so for proper XP name-ID and other bug fixes.
Google searching your particular make/model/revision of board
may turn up reports of particular CPUs being tried.
Also there may be a lot of info found by searching with
motherboard model name as a keyword at
http://forums.pcper.com/
Also you might check the motherboard manual and bios for the FSB
settings, to see what it already allows. However, not seeing 333
isn't necessarily a sign that it's not supported, but SEEING it
would be a fair indicator of what you'd need to change to get CPU
running at correct default speed if motherboard doesn't set that
automatically.