I second that!
I'm seriously looking into one of those new G3 upgrades from powerlogix myself.
It's exactly the same price as they're 533/550Mhz G4 zif upgrades but more than worth it. The Beige G3s need cache enabling software to even use a G4 cpu in the first place, aswell as this there are issues preventing the more recent 745x series of G4s from working with the beige G3 models according to some of the upgrade card companies.
Here's a little comparison between the 2 G4 types and the Sahara G3s.
The Sahara G3 (800Mhz powerlogix cpu):
4 pipeline stages : very efficient.
512K on die L2 cache @ CPU speed : very fast cache. Infact it's 6 x faster than the cache on the 266Mhz cpu.
0.13 micron process : smaller process means less power consumption/heat
SiMD Unit : None
The 7410 G4 (550Mhz Powerlogix G4 zif)
4 pipeline stages : very efficient.
1Mb backside L2 cache @ 2.5:1 of CPU speed : slower, less efficient cache.
0.18 micron process : runs hotter
SiMD Unit : Altivec
The 745x G4 (Used in current G4 models)
7 pipeline stages : not very efficient.
256K on die L2 cache @ CPU speed : tiny but fast cache, hardly efficient.
2Mb backside L3 cache @ 4:1 ratio to CPU speed (DDR) : just there to make up for the lack of L2 mostly.
0.18 micron process : runs hotter
SiMD Unit : Altivec
Or in non technical terms, the G3 is a far better cpu than the G4 for anything where Altivec doesn't offer a huge performance boost. Seeing as it's a beige G3 you havn't got the choice of using 800Mhz or 1Ghz G4 upgrades either.
To back this up,
barefeats did a comparison of the 667MHz TiBook to the 700Mhz iBook, eMac and iMac models. The 700MHz sahara G3 in the iBook is 20-35% faster than the 667Mhz G4 when altivec isn't used. Infact that's made even more impressive by the fact the iBook is running on a slower system bus than the TiBook.
