Saturday, 1 August 2009

Reviving an old PowerMac G4 Sawtooth

I've got myself a little project on the go after inheriting a 2000 model G4 PowerMac (AGP Sawtooth). I've only been a Mac computer user since the days of Intel so my knowledge of and familiarity with the PowerPC architecture is fairly limited. Initially, I though that this would be a side-project that might be easily upgradeable at relatively little or no cost, but I may have been wrong.

It's been testing my patience a little as all I got was the tower and no boot/install discs and the damn thing is temperamental at startup. The previous owner asked me to format the hard drive too. I will do that once I can get the damn thing to boot from the install discs that I already own when the original hard drive is connected. This has been a problem in itself.

Anyway, this is the spec (as far as I can tell):
The rest of this post is just going to contain notes and links to useful resources regarding the upgrade potential for my benefit (sorry folks - but I may be returning to it over the course of the next few days).


I've got a spare 80 GB IDE ATA/133 hard drive that the G4 just wont install to. It can see the drive when I connect it as the Master and boot up with OSX 10.3 install discs (hold C on bootup). I suspect that I need to install a new PCI IDE card in order for the drive to be recognised. Currently, the only option I've found in this regard is the Sonnet Tempo HD. It retails around $60 so is not a cheap solution to the problem. I might just attempt to reformat the original drive, although the G4 is a bit temperamental when deciding whether or not to boot up at all.

ACARD also offer an alternative solution in the guise of the AEC-6280M at around $70. Once again, not cheap, and also not so easy to source in the UK for import tax purposes. I've heard that SIIG used to offer a solution but they seem to be PC focused today.


I've also noticed a few companies that offer CPU upgrades for these old G4's. I've seen dual 1.6 and 1.8 GHz CPU upgrade options by companies like Sonnet. These retail at around the $300 mark. This is expensive enough to make you consider a second-hand G5.


RAM memory is dirt cheap. The G4 takes up to 2 GB of PC133 in 4 banks, available for a very reasonable price. Crucial will max the G4 out for around £43 which is at the expensive end of this upgrade path. Some eBay bargains can see you pick up 1 GB for about £10 a pair of sticks.

UK-based stores

There are a few decent places to go shopping for parts in the UK:
  • 2ndchancePCs - these folks are Sonnet resellers. They have the 1.6 GHz CPU upgrade listed at £313 after tax with the 1.8 GHz coming in way above that!
  • MacUpgrades - these guys have useful info on the various G4 models. They also list the Sonnet Tempo card at under £63
  • VIS Ltd - these people stock a variety of spare parts
  • There's always eBay for spares but it's not always great for this kind of thing
So, a quick reckoning of a basic CPU and HDD upgrade puts the costs at around £350-400. I'm beginning to wonder if it is worth the effort at that cost. If anyone out there knows of any other reputable or useful Apple Mac parts sellers that are UK/Europe based then be sure to let me know in the comments below or email me at

The problems

I can boot the system as it is but all I get to is what looks like an OSX 10.4 user login page. If I reboot with OSX 10.3 in the CD/DVD drive and hold down C I get nothing. A blank screen with no disc activity. This is a significant problems as this would be the most obvious way to get around the problem of needing to erase the drive and do a fresh install.

If I swap the original HDD out for the one I mentioned above (ATA/133) then the machine auto boots the OSX 10.3 boot disc as it cannot read the 133 drive as the IDE interface maxes out at 100. I can get as far as installing to the drive only to be told it isn't suitable.

If I plug both drives in, one as master and the other as slave (with appropriate jumper settings) the G4 refuses to boot at all. If I swap them drive orders around, the G4 refuses to boot at all.

I've also tried hacking the admin account but the [CMD+S] option doesn't respond so I can't bypass the GUI.


Nick Cope said...

Hi Rob,

I have an old G4 which can only support OSX 10.2.2, 10.3 and later will not run on it - 400MHz also.. much software and operating systems after that time are designed solely for faster machines..

Apple are notorious for not caring about backward compatability etc..

You could try installing 10.2 and see if its happy with that..

I'm just discovering my four year old G5 Power PC is destined to go the same way now Snow Leopard is out..

Rob said...

Hi Nick

Aha! I managed to fix up the old G4 no probs running 10.3.9 on it. It works fine but is slow as hell. Doesn't really support many video codecs but that's fair enough given it's a decade old

Yup, the G5s now are over in terms of future OS development but the last one was made nearly 4 years ago so they've had a few years, and will still be around for another 18 months at least, I reckon.

The new upgrade is literally a developers OS with very little benefit for general users. It's all about the gradual movement to 64bit architecture which has been happening for 5-6 years in the PC sector. Basically it's an attempt to unlock CPU clock cycles to make them efficient and 32bit architecture is unsustainable and incapable of doing that due to the limits placed on core data packet sizes. It's the legacy of the 32bit PowerPC days (and Intel Core Duo not Core 2 Duo - I own the former unfortunately). Their days are numbered.

However, unless you are a developer then OS 10.5 will be fine for another 18-24 months and there is no need to upgrade (see this Ars Technica review: . It will take developers that long to relearn how to program for the new architecture so any future end-user impacts will be seen in 10.7 I think

Funnily enough, most of the new changes in 10.6 come from the iPhone development which is a hell of a lot less powerful than those new Intel Macs. QuickTime has been totally rewritten and now no longer supports older codes like the Sorenson ones

tim said...

I could be completely wrong here but could this problem be because you are using an Intel based OS on a PowerPc system.

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