Sliced Apple - Choosing a Legacy Machine

Choosing when Choice is a Choice...

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Most people HAVE legacy machines that they end up upgrading. However others come across a system and buy it with the thought of upgrading it. It helps know what to avoid, and what you are getting...

This article dates from mid 2005 and represents the technology and my opinion from that time.

Legacy Systems to Avoid (confusing, not upgradable, you have got to Be Crazy...)

NuBus based systems. These are generally systems with three numbers or four numbers ending in 100, like the Quadra 850 or PowerMacintosh 7100/66. NuBus does not support OS X, any modern upgrades, and are slow. The NuBus system do not use PCI cards. Some PCI and NuBus systems shared case designs (such as the PM8500 and Quadra 850) so check.

PowerMacintosh 7200. Although a first generation PCI system the CPU is soldered to the board. It also has other low end features.

Rev A Beige G3. Requires an ATA upgrade to be useful, or you may be able to find a Rev B or C ROM for sale.

PowerBook 2400 and 3400 systems. Although they now have 10.2 installing on it, I wouldn't want to use 10.2 on a 603e based system with a 33 Mhz bus, a slow hard drive and less than 256 M of RAM.

PowerSurge Models: 1st Genernation PCI PowerMacintoshes (7200-9600, most clones)

This is the PM8500. These are very solid scalable and reliable machines that handle OS 10.2 through 10.4 well (although as a unsuported install such that installation, booting after problems, and trouble shooting can be involved) and do just fine with most PCI cards. The better ones, like the 8500/8600's and 9500/9600 were pretty powerful with features very useful in a machine past its prime. These features, such as more sophisticated memory controllers, can potentially operate much faster than the lower end systems, possibly even on par with the Beiges. They also have eight DIMM slots that allow 1G max RAMS even though each DIMMs is limited to 128K. They all have good (if older) SCSI buses with a faster internal and slower external bus.

They support a number of upgrade CPU's (they were the sweet spot at one point), have all the legacy ports (SCSI, serial, ADB, Mac video, Apple AAUX) some more modern ports (10base Ethernet, sound/in out) and do fine with cheap PCI cards for adding USB and FireWire. Remember Bertha is two years into this and only recently has she started to seem slow compared to the newer stuff (she is still just as fast but Apple hardware is getting much faster).

They are also cheap...but...they are also getting a bit beyond realistic limits for possible upgrades and it s not that cheap to max them out which is what is required. Unless one lands on your doorstep I would tend to get a little more recent system.

Avoid the PM7200. It was odd in that its CPU (a really old 601) was soldered to the motherboard making it nearly impossible to upgrade.

For me Bertha is valuable as a very good, versatile, and reliable Unix server and running my hobby and work websites, along with acting as a file server for achiving.

Early OS X server releases and OS X developer previews could be installed. The public beta was an official "unsupported" install meaning you could to it as you own risk. No shipping version of the normal OS X supports these machine. In fact the last version of OS 9 (9.2.2) doesn't either.

Gossamer and related: Original PowerMacintosh G3 (Beiges) through the First (low end) Graphite G4, Includes Early iMacs and iBooks along with some of the PowerBooks.

Gossamer was the internal development name for the new motherboards that appeared in the Beiges and original Bondhai iMacs, and then extended as the Blue and White G3's (Yosemite) and ending with the lowest G4 the Graphite G4 PCI graphics (Yikes).

This was a very transitional group and has numerous oddities. At this point Steve Jobs returned and brought NeXT (the Beiges were out) and started a 911 push to save the company. Jobs repackaged the Gossomer as the iMacs and PowerMacs making a rapid shift away from the tradition mac technologies like SCSI and rapidly abandoning all legacy I/O in a complete switch to USB and FireWire.

The Beiges were half way through the transition, having IDE but also having all the original ports. They were also "Old World" machines like the PowerSurge models meaning they had huge ROMS that contained large portions of the original Mac system, and were trickier to develop for.

In an effort to decrease ties to any one OS and to streamline development Apple changed to "New World" machines during the early iMacs that seems to coincide with FireWire. "New Word" machines had only little ROMS moving the content of the original ROMs to a drive file that was just part of the system. The also had the newer Open Firmware version with fancier boot support, etc... (a key reason why running OS X is even possible).

There is quite a bit of difference between the original PowerMacintoshG3 (Beige) Gossamer systems (Rev A-C) and the next generation Blue and White G3 "Yosemite" Systems, representing a large improvement of that basic Gossamer design with very little cost difference for a used machine.

The Beige Systems look very similar to the 1st Generation PCI PowerMacs, have a somewhat pokey 66Mhz bus, only 3 DIMM slots (so only 768 MByes of Max RAM), had ROM issues, squirrely IDE support, and no new ports. One model later the newer system were in the modern case design (that persisted in some form until the G5s), the "New World" architecture, had 4 instead of 3 PCI slots with the 4th one being a faster 66Mhz intended for video, a 100Mhz bus, 4 DIMM slots, and built-in (motherboard supported) USB 1.1 and FireWire 400 ports (2 each) which means startup support as well, and a Enet 10/100 port, plus things like sound in/out.

An Upgraded Beige with its three PCI slots immediately lost 2 of them (minimum) to a Video card (its included video was on the motherboard and was really slow) and at least a combo USB/FW card. That leaves one slot for such things as better Ethernet or wireless, a new ATA controller (which you WILL eventually want), SCSI cards, sound cards, or whatever else. Since the B&W had a dedicated video slot (which is twice as fast as a PCI slot on a Beige, or similar to a theoretical AGP 1x) you just swap that out, and USB or Firewire Upgrades are not required since they are already present. A cheap (like $25) combo USB2/FW/ might do great in a slot and that still leaves two of them open. The built in ATA controllers are not blazing but reliable (note they have their own limits in supported HD size). These are Gossamer done right and although much slower than the similar sounding Sawtooth systems based on the uni-north motherboard controller an upgraded Yosemite should crush a 1st generation PCI machine, and those have upgraded nicely.

Since these systems can be found for less than $150 and using standard PC 100/133 RAM and standard ATA Devices you could get one to 512MB of RAM and with a 60G drive or so for less than $200 and live with the OK video card for a bit.

I would normally consider these to be the obvious upgrade machine of choice for decent expandability for performance stuff (like CPU, video, drives) without wasting resources on basics (USB/FW/Enet) with a reliable and nicely performing resulting machine, but they all have a Gotcha that has caused some confusion in the Mac world because we are not sure how bad it is.

If you think back to the Rev A Beige with the "bad" IDE controller from its Rev A ROM the problem is not a bug or anything Apple would consider a real design flaw, it is a problem for upgrades. It worked fine with the drive it shipped with and still would. Apple designs machines to work the the hardware Apple puts in them, not whatever hardware we might put it them. PCI cards are an exception and the correct upgrade route. Motherboard level buses work in the cases and with the hardware Apple supplies and Apple does not imply, support, or care whether it works with your CPU upgrade, fancy new tech hard drive, or anything else. There is not often a problem (this stuff is standard) and the problems that do exist are often from transitional technologies (think PCI 2.0) and unexpected.

The Yosemite systems were G3 systems until the last version, the Yikes update, that had a G4 350. They all used a Motorola motherboard controller chip that everybody, even Motorola, was surprised to learn would not support a G4 CPU at greater than 400 MHz with a motherboard bus speed greater than 66. This was irrelevant to Apple when discovered a few years later since they never shipped anything like that and thus discovered by the CPU upgrade card companies as they tried to design the cards. This is a non-issue on the Beiges since they are 66 anyway but for the Yosemites you have a choice if you want a fast CPU upgrade, you can either get a very fast G3 based upgrade (PowerLogix's recommended approach) or a fast G4 based upgrade that automatically dials the motherboard speed back to 66 MHz. No matter what you give something up, either that nice 100 Mhz bus, or the G4 exclusive Ativec (the vector processing unit), and that hurts.

One factor often mentioned is that over most of the life of Apple G3 and G4 systems for most users there has been almost no difference in performance between G3 and G4 systems with CPUs of matched speeds. Only those using a few key Applications (like Photoshop) that took heavy advantage of Altivec really noticed. When I would run benchmarks they were typically the same. The architectural differences between laptop and desktops, or between having a slow vs fast hard drive, were usually much more important.

However that assumption may not be valid any longer, and getting a G3 upgrade violates "Rick's CPU rule". I consider any CPU that is not currently in a shipping Apple product to be a "dead" CPU. As long as Apple is using a given CPU in shipping systems the current released OSs are highly optimized for them and new technologies at least consider how to deal with those CPUs. Once they are out of Apple's line up they cease to be as much of a consideration as the OS design team adds new features and optimizes for the shipping CPUs such that the older ones rapidly degrade in performance and really have a very limited life. You can watch the process and know it is coming: Two CPUs, A for the Low end and B for the High end, then A is gone, B is Low and a new C is High...

G3s are gone, G4s are low, and G5s are high. G3s were around for a long time and I think G4s will have a place in Apple's line up for some time, although probably confined for a large part of it to iBooks. I would give the G4 a "live" lifespan of about 2 more years and that makes it an upgrade choice.

Also lots more software that you are likely to use uses Altivec and what is fun on a G4 (playing with iMovie transitions) is just not worth it on a G3 and what seems to take a long time on a G4 (ripping DVD's at several hours to 24 hours) takes so long on a G3 you eventually have a power outage or apes take over the planet (think days).

I have been VERY impressed by finding (via Bertha) how well a G4 with a big cache can work around the performance impediments of a slow bus. For almost every use the PM8500 with the G4 800 felt exactly the same as the PowerBook G4 867 that had a memory/bus architecture (133 Mhz bus with DDR 266 MHz RAM) that was much better than the PM8500 (50 MHz bus and FPM DIMMS that were even slower than 50 Mhz) but also had smaller caches.

There is no way I would get an expensive G3 upgrade. It is possible that the G3 cards, since they preserve the bus, might provide performance advantages over similar G4 cards for some time, but not huge ones, but it is also likely that they will rapidly be much less useful. If you intend to use a machine for a couple of years G4s are a safe choice, G3s are a gamble.

10.0-10.2 supported anything Gossamer or better which means anything fromm the orginal PowerMacintosh G3 to the present.

10.3 required machines with built-in USB which eliminated those first Beiges but includes all iBooks and iMacs. This change was easy for XPostFacto to work around since the Beiges and iMacs are basically identical.

10.4 requires (for a supported instal) "New World" machines which means Built-In FireWire. This would start at the B&W G3s, and the iMac, iBook, and PowerBook FireWire versions.

Sawtooth and related (UniNorth): This spans most recent history (as of mid 2005) starting with the original Graphite AGP G4 (sawtooth) and the majority of systems short of the G5s.

The change from Gossamer to Sawtooth was a major advance and the Sawtooth design and continued to form the basis of most newer systems. Sawtooth incorporated a new much faster memory controller (UniNorth) that provided a 2 x improvement in basic bus performance, options for internal Airport including an integrated antenna in the case, an AGP slot for the Video card (2 - 8x times over the whole generation), a v90/92 modem, VGA and DVI/ADC video, much faster ATA 66/100/133, plus all the standards like 10/100 or 10/100/1000 Ethernet, USB 1.1 with USB 2.0 more recently, and FW400 with FW800 more recently.

Benchmark differences comparing machines from the Sawtooth line against what would appear to be a very similar machine from the prior architecture show stunning differences. Comparing the Yikes G4 (Graphite PowerMacintosh G4 350 (PCI Graphics) ) and the first Sawtooth G4 (Graphite PowerMacintosh G4 400 (AGP Graphics).these systems appear to differ only in a slight CPU speed gap and AGP vs PCI video. In reality the Sawtooth is leaps and bounds faster.

The Graphite PowerMacintosh G4 350 (PCI Graphics), what most people refer to as the PCI G4, and the Graphite PowerMacintosh G4 400 (AGP Graphics), typical called either just Sawtooths or AGP G4's, sold at the same time for a bit with the orginal PCI platform for the lowest level pro machine and the AGP for the middle and high ones.

These AGP G4s are the sweet spot in the current environment since their upgrade potential is virtually unlimited (G5 upgrades are surely coming) and everybody knows it. The used cost more than doubles as you cross generations from the older Gossamer based systems, and the really high end CPU upgrades are produced for the AGP G4 based systems.

I have the original AGP G4, the Graphite PowerMacintosh G4 400 AGP, on semi-permanent loan to my parents that I did before I started this new much larger interest in upgrading and modding, and I sure with I had it back.

A Bit About Laptops

Laptops have very different design considerations and tend to lag a generation behind the desktops in their real architecture, a fact that is not always obvious since their technical marketing specs (ports, etc) tend to match same generation desktops. Another trend is today's PowerBooks tend to be tomorrow's iBooks.

That tendency is not law however.

A few markers in the laptop continuum:

Before the PCI based Macs the bus architecture was Nubus. Nubus was much slower than PCI. The PowerBook5300 and the 1400 were nubus based but the immediately following PowerBook 2400 and 3400 series were PCI based and essentially tech equivalent to their desktop brethren.

The original iBooks were Gossamer based as were the WallStreet and related PowerBooks. The iBook dual USB (the first white one) were essentially the prior generation PowerBooks (like the WallStreet). Meanwhile the PowerBook line progressed to the UniNorth based chipset (Titanium). The iBooks transitioned during the mid white industrial design phase to the UniNorth base around the time the PowerBooks progressed to DDR memory and the aluminum casing. The iBooks caught the PowerBooks when they transitioned to the G4 design and at current are essentially the same system with slightly lower specs, but with 50% longer battery life and longer Airport range.

A Bit About Clones

Cloning was a short lived part of Mac history. Clones can have some unique issues but typically they match similar Mac hardware being based on Apple reference designs. The clones were 1st generation PCI Macs like the PM8500. Some of their OEM hardware and possibly chipsets were odd but generally involving upgraded items anyway (like video, Ethernet). Clones are good upgrade systems also having the advantage of really standard ATX layouts.

I upgraded a PowerComputing PowerCenter 120 which is the clone cousin of the 7500/7600 line (but more like a 7200 motherboard) and it proved no more difficult or less stable than the PM8500.

It is minimally upgraded and a little slow but runs very well as a server, or just to surf. Most of this page was authored on it using Nvu without any problems.

Some of the Starmax systems have issues with certain upgrade cards and some of the PowerComputing systems have odd display cards or motherboards that are not supported.

Conclusions

The best system to upgrade if you are interested in a real legacy system (not supported by 10.4 officially) would be a Blue and White G3. Sonnet's G4 700 upgrades is currently listed at $199 and you can probably find it cheaper. Check out the other makers as well. Other required upgrades would be some PC100/133 RAM and a larger ATA HD (don't go over 120G).

This machine should easily trounce Bertha, have none of its PCI issues, and take full advantage of ATA and USB 2.0 PCI cards. The Gossamer based machines currently support 1 GHz G4 upgrades.

This system would be a supported Panther install.

The best upgrade system would of course be one of the early AGP G4s. They are supported on OS 9 and all versions of X (through 10.4), and can take an upgrade AGP card to run Quartz Extreme without hogging the bandwidth.

If I were looking I would not buy one of the first generation PCI systems. Although they work well they are too near their limit. Also any affordable hard drive is ATA such that these systems almost require a $100 ATA PCI card but a B&W G3 came be with ATA, USB and FireWire already in place. The upgrade cards are likely more expensive as well. This sets the entry price around ~650 to bring an original PCI beast up to some kind of par, but around $400 for the B&W which would NOT be maxed and be significantly faster. (based on G4 700, 1G RAM, USB/FW, ATA 100/133 120 GB hard drive.)

Of course the B&W would run acceptably with NO upgrade CPU card bringing the basic price to $200.

Laptops are lousy upgrade systems.

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Created 05/28/05
Modified 01/09/26 - numerous spelling and punctuation errors fixed, and I am sure many more remain
Modified 01/19/29 - clarification/links/cleanup