Chris, I bought one when they first came out, along with a ATI Radeon 8500, and have not been sorry. I have had two years of rock solid operation at a little over twice the original performance. Combined additional fan noise is noticeable, but nothing like that which plagued later G4s. If I were going to purchase a cache card for a G4-400, now, I would probably add a $100 and buy an OWC Mercury Extreme G4/1.25-1.4GHz 2MB SDR L3 Processor Upgrade. Suggest you read some of the user feedback on the various accelerator cards at http://www.xlr8yourmac.com/. Mike >I have a G4 AGP 400 MHz that I'd like to squeeze a little more >performance out of. I'm looking at the 1.4 GHz Powerlogix Powerforce >G4 100 processor upgrade. Transintl.com has them for $398 according >to DealMac. > >Has anyone else installed one of these? What actual performance >difference did you see? Any other upgrades I should be looking at? >-- > >--- >Chris Smolinski >Black Cat Systems >http://www.blackcatsystems.com -- Almost never pointless.