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Could new CPU Upgrades for PowerPC macs come out in the future?


Well-known member
So I saw a forum on macos9lives.com (also a member there) that talked about if it was possible to make modern cpu upgrade cards for the power PC machines. Heres a link: http://macos9lives.com/smforum/index.php/topic,5076.0.html

Well, now I'm curious if anyone else is interested in this idea. Modern CPU upgrades for the PowerPC Mac's would make some hard to find upgrades more acessable. In addition, we could also make some new upgrades that weren't thought of back then. For example, making a G4 upgrade card for a 68k mac or making a replica sonnet harmoni g3 but with a G4 CPU or even create a G5 upgrade to the eMac. Those would be cool.


Well-known member
slightly not the same topic but: funny enough I had somewhat asked about cpu carriers before as I was thinking re (still am thinking!) producing a small batch of zif cards that would accept the many inexpensive/bulk ibm cpus found online


Well-known member
The Amiga community might be more interested in new CPU upgrades than the Mac community.

Imagine PPC support on the PiStorm…


Daring Pioneer of the Future
Staff member
This is already happening at small scale: Forum member @herd has a thread here https://68kmla.org/bb/index.php?thr...c-also-complete-computers-usa-shipping.38413/ where some upgrades and swaps are taking place. I believe @LightBulbFun and @max1zzz are also doing some, but I don't remember off the top of my brain where their threads are. (Sorry!)

There's also this discussion: https://68kmla.org/bb/index.php?threads/so-i-bought-a-1ghz-7455.38975/ from one of the people you see in that OS9Lives thread where someone else is going down basically the same general path of putting a new CPU on an existing module or using newer CPUs to build a new module.

There's a couple other discussions, @trag is in on a couple.

I think the real limiters are whether or not these CPUs are still being built and whether "someone" who wants to build the upgrade modules can get the right connectors and a board made, or, a steady supply of donor modules to be swapped.

Proverbially, the sky is the limit and it's super fun to see a reupped interest.

For the most part, where this is landing is re-creating what Sonnet did in early 2007 with its 1.8/2.0GHz upgrades for some G4-class machines. Prior to the launch of Adobe Creative Suite 3 (The Universal Binary version) Sonnet strenuously advertised that a 2GHz G4 could outbench a 2GHz CoreDuo in some Creative Suite 2 tasks, so, there are definitely some gainz to be made.

Doing some CPU swapping on a Mini G4 and on MDD G4 modules is probably where the best gainz are to be made, since you can start with a platform that has a 166MHz bus instead of a 100-133MHz one.

For anything older than a PowerMac G3: I think that the potential for those machines is essentially already fully tapped out. The Mach5/Kansas 8600 and 9600 have 50MHz buses and you can, nominally, put a 1GHz G4 on them. It's, if I'm remembering correctly, meaningfully slower than a 1GHz on a 100/133/167 bus. Would a PCI PowerMac with a 2GHz G4 in it be fun? Yeah absolutely. Would it be any better than a stock 1GHz QuickSilver'02? No probably not.

Not that people shouldn't pursue this, but:
The big bummer is that even on 166 bus platforms there's definitely a practical upper ceiling for how much a faster CPU will help. To be straight-up, Mac OS 9 barely takes advantage of anything more than about 300-500MHz of G3 or G4, and can not effectively use more than about 512 megs of RAM on the outer reaches of reasonability for most workflows. Mac OS X can, but, I suspect interest in faster PPC upgrades died after about 2007 because, well, a 2GHz Core2Duo should very much outperform a 2GHz G4 when both are running native code. (It's also fairly close even when running PowerPC code under Rosetta.) For OSX/PPC code you can buy a Mac Pro 5,1 or any of the early-mid 2011 Macs, all of which run OS X 10.6 and Rosetta and, to be honest I bet you could outbench any G4 or G5 at PowerPC software in that way.

Is a 2GHz G4 fun? yes.
Is a 2GHz G4 practical? maybe not -- but that doesn't mean we shouldn't do it. (And, a lot of what seems to be happening is increasing the availability of >1GHz upgrades for older machines that shipped with 400-1200MHz CPUs, and that's good for sure.)


Well-known member
There's a couple other discussions, @trag is in on a couple.

I haven't finished much in the last 13 years, so I'm not encouraging anyone to hold their breath for me to get anything done.

I did just (finally) finish the PEx ROM project, so I have fresh ambitions.

I'm kind of distracted by the Acard SCSI/IDE adapter at the moment, but what I really want to do in the next few weeks is convert the Acard 6880 cards I have on hand into 6880M. And convert this box of Sapphire Radeon 7000s into Mac cards.

Neither of those is real exciting, but I've had these things log-jammed behind the PEx project for a long time and finishing them will begin the process of getting some boxes out of the house.

The 6880M is slightly exciting, in my opinion. The reason being that the card supports RAID 0 or RAID 1 and it works under Classic and OSX. That means that, as far as I know, it is the only way to have a redundant (or striped) array that will work whether you're booted into 9 or X.

Eventually, I would like design/make some CPU cards for the X500/X600 family using PPC750GX/GL chips. Those just need a properly fabbed circuit board to be an edge connector, and don't require a PGA header, like the ZIF cards do. I'd love to make some ZIF cards, but that darned header is a problem.

I'm also interested in experimenting with some faster/larger L2 caches. If nothing else, one of these days someone needs to make a 1MB cache for the X100 series to make @Bunsen happy. IIRC he's been looking for one of those for close to 20 years.


I'm interested in doing interposer adaptations of 603e QFP pads to G3 BGA for a few favorite machines like the 2300c. That discussion was one I had with the member who wanted to do a PPC upgrade for the Blackbird, IIRC. There was a lot of discussion about appropriate CPU for such nonsense.

Since then I've found information on how to solder the interposer to the processor's pads. 😬


Daring Pioneer of the Future
Staff member
I’m kind of surprised no one has made an Amiga upgrade based on POWER9.

I had my sensible chuckle. I wonder if there's any Amiga people working on porting anything to Talos machines. There's other PPC "Amigas" which are really just router-aimed powerPC CPUs with a Radeon strapped on.

Neither of those is real exciting

Sometimes the things that are important for the overall scene aren't very exciting. I've been cheerleading for a few things for several years that aren't "exciting" but are probably important to have long-term, so, increasing the supply of available HBAs and graphics cards is a great plan!


Well-known member
I think Maybe make modern G4 cpu cards on G3's or G5 cpu cards on G4's would be cool, but everyone is open to their ideas. Making replica upgrade cards would make them more acessibble to the retro-community.