G5 upgrades for Mac OS 9

[Mat]

The last days I learned that the IBM PPC 970 is through its built in VMX absolutely code compatible to the G4 CPUs. So I was asking myselve why never any upgradecard with an G5 appeared for the G4s? Do you know about any special problems (aside the heat) of the G5s? some of the later G4 upgrades are datet 2006 or even 2007 if I am not wrong. A time when the G5 was already extensively in use. So why did non of the companies produce any G5 upgrades?

Even with clean 32 Bit usage, a 2,5 GHz 970 would be a great upgrade to an 1,4 GHz G4, ...

Any knowledge what might have been the issues for sonnettech, newer, fasc mac, powerlogix and others? I suspect that they avoided to use a G5 because they could never offer a true 64 Bit operation with such an upgrade. But as it is not needed for Mac OS 9 there would perhaps be a chance to create such a clean "built for Mac OS 9 upgradecard" these days?

Do you see any chance to produce such an upgrade today,  and what would you expect, and what would it need to do for you, that you pay a lot for it these days?

[Protools5LEGuy]

Check http://macos9lives.com/smforum/index.php?topic=947.0

I think Apple choose the wrong chip with the IBM G5. It should be used only on towers, and kept working on Freescale designs.

https://en.wikipedia.org/wiki/PowerPC_G4

https://en.wikipedia.org/wiki/PowerPC_e600

They could have make portables with the e600.

Were the latest iBook G4 and Alu PowerBooks use this MPC7448 from Freescale?

The PowerPC 7448 "Apollo 8" is an evolution of the PowerPC 7447A announced at the first Freescale Technology Forum in June 2005. Improvements were higher clock rates (up to 1.7 GHz) officially and easily up to 2.4 GHz through overclocking, a larger 1 MB L2 cache, a faster 200 MHz front side bus, and lower power consumption (18 W at 1.7 GHz). It was fabricated in a 90 nm process with copper interconnects and SOI.

PowerPC 7448 users were:

    Daystar for their High-Res Aluminum PowerBook G4 upgrades (Daystar's Low-Res Aluminum PowerBook G4 upgrades used the 7447A, not the 7448)
    NewerTech for their Power Mac G4 upgrades
    PowerLogix for their Power Mac G4 Cube upgrade
    Cisco in NPE-G2 network processor module for their 7200VXR routers

They introduced in 2007 the MPC8641D and MPC8641 that could have won over a Core Solo processors easily, but one year later of Apple decided to go Intel...




Maybe a brilliant team of engineers in OWC could make the last batch on CPU upgrades for our G4 machines based on these ones. They consume less than our G4s.

It's plausable to think they could design a Quad G4s using 2 dual core e600 in a daughter board. And probably at a lower temperature.

[Protools5LEGuy]

Just wanted to add that I believed this for months:

http://lowendmac.com/2003/apple-g5-upgrades-no-mac-left-behind/

[Mat]

Well, recent e600 Core CPUs like the 8641(D) clock at 1,5 GHz maximum. So there is no huge improvement over our MDDs, as long as we don´t have powerful multiprocessing hacked into Mac OS 9. But a G5 is deliverable, clocks at 2,5 Ghz and can be overclocked as well. So regarding the amount of work, a G5 used in clean 32 Bit could be the most powerful upgrade to our Mac OS 9 machines. That was the idea and what I wanted to discuss.

On the other hand the overclocked 7448 in 2GHz are in existance (by FastMac and Newer if I remember correctly), and another series would perhaps be the cheapest possibiliy, and much easier to achive than a new developed hardware. So I don´t see any point in another e600 upgrade at the moment. This might change with Multiprocessing and higher clockrates.

[nanopico]

Besides apple wanting to leave OS 9 behind by the time the G5's were available.
Third party G5's would be a problem.
Although in 32 bit mode they are code compatible, because they are 64 bit processor the mum runs at 64 bit's no matter what and a lot of 32 bit MMU instructions are not supported on the G5.
These could be emulated in software, but you would have to write an OS patch to emulate those as Apple would have not added that code into OS 9.
These patches would have to run very very early on to even get a machine to boot.

The other issues the interfacing hardware wise between the G5 and the rest of the system.
The line of G4's would not know well enough how to speak to the G5's enough to even boot Open Firmware.

[Mat]

Thanks nanopico for that important informations. Thats what I feared, so th theoretically code compatibility in 32 Bit is of no help because of other issues like the MMU. This explaines as well why no company ever tried to create such an upgrade card.

So the G4 is our only option. The question is now for me how a MPC8641D in single core usage performes compared to the 7448? Are there any informations around anywhere?

[MacTron]

The other issues the interfacing hardware wise between the G5 and the rest of the system.

That's the main reason because a G5 upgrade for G4s couldn't ever exist. The G5 uses a very very different system bus called E-Bus (or 970-bus) while G4s uses the MaxBus (also known as MPX) in the MDDs or the 60x bus in the QuickSilver and older models.

The MPC7448,MPC8641 and MPC8641D uses the same e600 core, but the MPC8641 and MPC8641D can't be used in upgrade cards because both are SoC, not estandar CPUs.