68kMLA Classic Interface

The Rage Pro doesn't provide that much of a performance boost to the existing onboard video, I'd go for something like a Radeon 7000 or 9200 (if you can find one). The G4 card should work but you need to adjust the clock speed, I think. The beige systems run at 66MHz FSB and the B&W/Yikes! run at 100MHz. Not sure about enablers or extensions, it should work under at least Mac OS 8.6.

G4 swap will work with correct jumpers set on the motherboard, and check you have the Altivec extensions installed if running Classic Mac OS. They don't overclock much even with a higher multiplier but you can always try.

The ATI Rage Pro isn't far off what's onboard, the Apple Rage 128 Pro PCI is cheap enough and would give a boost, while a Voodoo 3 or Voodoo 2 for games even better.

Yes, Altivec and L2 cache both need to be enabled through software. I strongly recommend XLR8 MACh Speed 3.5.0 under Mac OS 9.x, I had lots of problems with Powerlogix CPU Director.

A Rage Pro might not offer any performance boost at all depending on what's onboard. Even something as modest a Rage 128 would be a far better upgrade.

Thank you for your replies.

When I swapped the original processor (266/512kb) for the G3 B&W (350/1MB), clocked at 400MHz, Apple System Profiler automatically showed 400MHz and 1MB of cache! So, as I understand it, swapping for a G4 and having OS 9.2.2 should work fine, right?

If I decide to install 8.6, then do I install XLR8 MACh Speed 3.5.0? Will this activate Altivec? OS 9.2.2 already includes it by default.

I have the ATI RAGE 128 graphics card with 16MB of VRAM from the G3 B&W, I understand that at least the increase in VRAM will be an improvement, right?

P.S. @croissantking, were you the one who tried swapping the chipset for one at 100MHz and couldn't get it to work at that speed? Tested with a G4?

I’m not sure how it would be able to show as 400MHz without you changing the multiplier on the jumper block. That’s very strange indeed. But the larger cache enabling automatically is expected and correct.

I use NewerTech Gauge Pro to verify speeds which is much more reliable than System Profiler, I would take with a pinch of salt anything ASP says.

As for cache, a Beige G3 won’t be able to enable a 7400’s L2 cache without third party software. So you need MACh speed etc.


I think so.


A Rage 128 is substantially better than onboard video.


Yep that was me. And nope I couldn’t hit 100MHz although I did get close. Yes I did test with G4.

Excuse me, when I mentioned that I installed a 350MHz processor running at 400MHz, I assumed you knew I had changed the jumpers. That wasn't a problem.

Regarding enabling the L2 cache when swapping for a 7400, I remember installing an XLR8 extension on my iMac to change the cache speed before modifying the firmware. I suppose it will work; it's the extension that installs when you run CPU Director. Would that work?

It's a shame this machine can't run a 100MHz bus; I have a chipset I could have swapped.

Oh! I already installed the ATI Rage Pro 16MB 🙂

CPU Director is Powerlogix, not XLR8, don't get confused 🙂

I think we are getting confused here as well - the Rage Pro is not the same as a Rage 128. The Beige G3 came with either a Rage II+ or a Rage Pro. The 128 is substantially better.

When I swapped the original processor (266/512kb) for the G3 B&W (350/1MB), clocked at 400MHz, Apple System Profiler automatically showed 400MHz and 1MB of cache! So, as I understand it, swapping for a G4 and having OS 9.2.2 should work fine, right? If I decide to install 8.6, then do I install XLR8 MACh Speed 3.5.0? Will this activate Altivec? OS 9.2.2 already includes it by default.

Ah OK.



CPU Director is Powerlogix, not XLR8, don't get confused 🙂



Yeah, the clock generator won't go that high. It has built in presets and 83.3MHz is the maximum. I experimented with changing the reference crystal and was able to push it up to about 96MHz, but once you start adding in extra RAM and a faster CPU, the PLL sags. I eventually settled on ~87.3MHz.



I think we are getting confused here as well - the Rage Pro is not the same as a Rage 128. The Beige G3 came with either a Rage II+ or a Rage Pro. The 128 is substantially better.

I can't find the original thread, but swear I remember reading here that unless the G4 was in the machine when OS 9 was installed, Altivec support would not be enabled.

I'm not sure whether it's as simple as dragging and dropping an extension (or installing one from an upgrade manufacturer) after the fact.

I write very fast and omit information, sorry, I always refer to the same thing, the 128 that came in the G3 B&W, with the expansion to 16MB

That expansion isn’t VRAM, it’s a DVD decoder.

I was told that the DVD decoder was made redundant by the G3 main processors getting fast enough to do the job themselves. That's one reason you see so few of them… at first they simply cost extra, and by the time that was less of an issue, they were no longer needed in the first place.

Ah OK.



CPU Director is Powerlogix, not XLR8, don't get confused 🙂



Yeah, the clock generator won't go that high. It has built in presets and 83.3MHz is the maximum. I experimented with changing the reference crystal and was able to push it up to about 96MHz, but once you start adding in extra RAM and a faster CPU, the PLL sags. I eventually settled on ~87.3MHz.



I think we are getting confused here as well - the Rage Pro is not the same as a Rage 128. The Beige G3 came with either a Rage II+ or a Rage Pro. The 128 is substantially better.

I was told that the DVD decoder was made redundant by the G3 main processors getting fast enough to do the job themselves. That's one reason you see so few of them… at first they simply cost extra, and by the time that was less of an issue, they were no longer needed in the first place.

With the original 350MHz G3 processor, I tried setting the L2 cache to 267MHz and it froze—it didn't work—but with this G4 processor, I made the same adjustment and it worked! With the processor running at 400MHz, the cache ran at 267MHz! They are the same chips; I haven't replaced them.

So I decided to test the processor at higher speeds. I first set it to 566 MHz, but it wouldn't boot—I didn't even hear the startup chime—but then I set it to 533 MHz, and it worked!

It runs completely stably, but Daystar reports a temperature of 52–56°C with almost no CPU load, so I decided to replace the heatsink. I adapted a generic graphics card heatsink with a fan. It is made of aluminum—and I might look for a better one later—but for now, it works well; the temperature has dropped to 32°C.

I'm happy with the result. Sorry, @croissantking, that I didn't try to increase the bus speed; if someone with your skills couldn't reach 100 MHz, I wouldn't be able to either. If you manage to do it, let us know!