I realize this isn’t exactly the right site to ask this sort of question, but I didn’t know who else to trust with a problem of this world-shaking magnitude…I was wondering, simply, if it would be worth it to try and upgrade the processor on my Power Mac. I figured someone else here would have faced a similar quandary. I haven’t had much experience tinkering with computer hardware, so I don’t know if any available CPU upgrade would even be able to boost my performance appreciably. And I’m not looking to do any heavy-duty industrial level computations or anything, I’d just like to be able to get a good frame rate on the new versions of my flight simulator…and to get my system up to the level able to support “Return to Castle Wolfenstein” and “Medal of Honor.” 
My computer is a 400 mhz G4, at the moment. (Though I got it after Apple had upgraded motherboards in the 400 mhz G4s from the old G3 type) Purchased in early 2000.
Can anyone help?
Thanks for your patience,
Ranchoth