G4 processor upgrade?

Yes.

There are used, 3rd party processors from Gigadesign, Fastmac, OWC, Newertech and Sonnet that will work in most any G4 tower.

Other thoughts:

http://www.jcsenterprises.com/Japamacs_Page/Processors.html

japamac, please excuse my butting in, I was wondering if you have an info. or thoughts on CPU upgrades for a G 4 PCI "YIKES" machine ( was a 400 Mhz, now has a Sonnet G 4 500 Mhz CPU ) .... i have read your pages and web site, and didn't see anything specific about this "YIKES" animal. .... I would like to boost it to 800 Mhz or MORE ????? If possible without a lot of hassle, prefer a "plug and play" solution. It is the "ZIF" socket type processor socket.

Thanks, wayne146 ..... and sorry for jumping in .....

Here's a list of potential boosters:

http://www.everymac.com/upgrade_cards/by_system/powermac_g4.html

You'll likely find a Sonnet if you look around.

The following reading will likely answer your questions:

http://www.xlr8yourmac.com/G3CARDS/G3_1.1GHz_vs_G4_1GHz_review/index.html