AP400

Hello I am trying to Upgrade My AP400 PWS (Pro work station) With another
CPU. I already have a 700MHz CPU so i thought it good to get another same
CPU of same rating. I notice that the slower CPU's (600MHz) have 512Kb of
cache rather than the 700MHz CPU's 256Kb of cache. So if i have two CPU's of
these types which is faster?? also do you guys have the part numbers for
these (My AP400 is at my parents house at mo probably getting clogged up
with spyware cos of my Bro!!!)

P.s maybe i can put faster slot one CPU's in??? or maybe even a SLOCKET??

Thanks for help don't hesitate to ask about AP400 issues (I've had most of
them)