PowerMacG3/300 DT

[Quadraman]

"Any Beige G3 can be readily upgraded to a 400-500MHz G3 via a ZIF processor transplant from a Blue and White"

I do not believe this is correct. The Blue and White has a 100mhz bus speed, the beige is only 66mhz. There will be issues if you try to swap newer CPU's into the older machines. Also, there were no 500mhz B&W's. 450mhz was as high as they went.

 

[Quadraman]

Mind pulling the CPU and giving us the numbers on the two black surface mount chips that are on the top of the ZIF module? (there should only be two like it on the entire thing IIRC)
*Edit

but you cannot argue against Apple's own page concerning the beige G3 having only having 512k cache.

Quadraman, don't forget that the 300Mhz and 333Mhz models had 1MB L2. I can verify this as I do have a 300Mhz CPU from a beigew/ 1MB L2 that would not overclock to 350 in a B&W G3 without interesting screen artifacts.(IIRC they were transparent lines that changed size&position as certain things moved and changed size, like icons in the Dock and certain parts of Finder windows and such.)

Please note that all my links are for the 266mhz desktop models, which is what I am trying to show Metalchic. Try to follow along.

 

[Temetka]

"Any Beige G3 can be readily upgraded to a 400-500MHz G3 via a ZIF processor transplant from a Blue and White"
I do not believe this is correct. The Blue and White has a 100mhz bus speed, the beige is only 66mhz. There will be issues if you try to swap newer CPU's into the older machines. Also, there were no 500mhz B&W's. 450mhz was as high as they went.

That's what the jumpers on the motherboard are for. You can adjust the multiplier and front side bus settings. Some people like me were even blessed with motherboards that are stable at 83MHz. This setting leaves the 33MHz PCI bus speed intact. My Rage Orion (32MB) is pretty happy on this speed.

 

[Quadraman]

"Any Beige G3 can be readily upgraded to a 400-500MHz G3 via a ZIF processor transplant from a Blue and White"
I do not believe this is correct. The Blue and White has a 100mhz bus speed, the beige is only 66mhz. There will be issues if you try to swap newer CPU's into the older machines. Also, there were no 500mhz B&W's. 450mhz was as high as they went.

That's what the jumpers on the motherboard are for. You can adjust the multiplier and front side bus settings. Some people like me were even blessed with motherboards that are stable at 83MHz. This setting leaves the 33MHz PCI bus speed intact. My Rage Orion (32MB) is pretty happy on this speed.

Most Beige G3's cannot be overclocked to 83mhz. It depends on the components on the motherboard. Some motherboards actually had parts that were rated for 83mhz but most do not. Changing the jumpers does not work on every G3.

 

[alk]

Many rev A boards are capable of 83 MHz, but I've yet to come across a Rev B board which can be clocked that high and be stable. But that is beside the point. The jumper settings on the board will allow 500 MHz on a 66 MHz bus with no problem.

Peace,

Drew

 

[Quadraman]

Many rev A boards are capable of 83 MHz, but I've yet to come across a Rev B board which can be clocked that high and be stable. But that is beside the point. The jumper settings on the board will allow 500 MHz on a 66 MHz bus with no problem.
Peace,

Drew

That isn't the issue, though. The issue is that the later CPU's set their own multiplier independent of the jumpers, don't they? That's the reason I was always given why ZIFs from B&W and Yikes! won't work in the beige G3.

 

[MacJunky]

I have a 350Mhz CPU from a Rev 2 B&W running at 433Mhz @66Mhz bus in my Beige.

The only thing I can think of what you mean would be some of the third party upgrades but IIRC the faster ones automatically detect the bus speed and run at the right speed like many of the later AGP containing G4 ones do.

For example, the sonnet encore(ZIF)

The Encore hardware automatically configures the correct bus ratio without the need for switches.

 

[alk]

That isn't the issue, though. The issue is that the later CPU's set their own multiplier independent of the jumpers, don't they? That's the reason I was always given why ZIFs from B&W and Yikes! won't work in the beige G3.

Apple hardware wasn't that smart. 3rd party hardware can be (Sonnet is particularly annoying with their "simply fast" mantra). I have a 450 MHz G4 7410 ZIF that has smarts on it. It is designed to be a drop-in replacement for the G3 in both beige and B&W models. So the card recognizes the bus speed and sets the appropriate multiplier to get to 450 MHz. I clocked my beige G3 to 83 MHz bus speed, but I can't get my G4 up to the rated speed because of those supposed "smarts."

I have also heard that you aren't supposed to use Yikes! CPUs in earlier Macs. The cache doesn't get enabled properly because the G4 and G3 have a different cache configuration. The ROM doesn't know how to turn on the cache. It still might be possible with a 3rd party cache enabler...

I don't know if this is true on the B&W, though.

Peace,

Drew

 

[Temetka]

I have heard nothing of the kind.

CPU's are very simple in this regard. Bus, Multiplier and Cache. Just set the multiplier and the bus speed and you're good. I have NEVER had to use a 3rd party utility to enable the cache on any of my ZIF CPU's (G3 or G4). I have had to do it on the Mach V systems though. Perhaps that is where some of the confusion is coming from?

 

[alk]

No. Are any of your ZIFs genuine Apple G4 CPU modules?

Peace,

Drew

 

[Temetka]

No. The G4 is from OWC.

I have a weird powerlogix G3. It's got a multi-position switch on it. Think rotary dial type thing. Can't find any documentation on it. Chip markings point to 500MHz and while my B&W runs fine in Classic w/it, it borks in X. I think I might not have it set right from guessing blindly.