The name Power Macintosh G3 refers to two seperate lines of IBM/Motorola PowerPC G3-powered computer, both referred to as the "Power Macintosh G3". The earlier line features "traditional" Apple cases, and is known as "Beige", whereas the newer units have the now-familiar translucent blue (blueberry) and white (actually frosted clear) cases, and are known as "Blue & White". The two systems differ in every regard but their CPU and choice of bus (PCI). As the name suggests, this is the third generation of Power Macintosh computers.

One thing that both lines of G3 systems have in common, however, is problems with their IDE support, specifically problems supporting slave drives. The revision 1 Blue & White (Hereafter "B&W") G3s also have a data corruption problem when using most aftermarket hard drives, which must be solved by installing a new IDE controller, or with the use of third party software.


The first Power Macintosh G3 systems (code named "Gossamer") were the 233MHz and 266MHz versions, released November 15, 1997. They came with 32MB of RAM, upgradable to 768MB of PC100 SDRAM by filling all three DIMM slots with 256MB each. They provide onboard ATI 3D Rage II+ or Rage Pro video (depending on revision) with 2MB of VRAM upgradable to 4 or 6MB. Both systems have 512kB of L2 cache memory running at half the CPU speed. They both came with 6GB EIDE hard drives, and 24X CD-ROM drives. Also notable is their abundance of legacy I/O: They have one ADB (Apple Desktop Bus) port, two DIN-8 GeoPorts (RS-232/RS-422 serial ports), a DB-25 SCSI connector, and AAUI and 10Base-T ethernet. These are the last macs to have serial ports, though not the last ones to have ADB. These macs have 3 PCI slots.

There are a number of CPU upgrades available for the Beige G3s, which plug into the ZIF CPU socket, up to and including a 1 GHz G4. You can also get the Firewire and USB ports that the early G3s lack on a single PCI card, though it can be somewhat pricy.


The Blue & White Power Macintosh G3 (Codename "Yosemite"), released January 5, 1999, is in some respects the first truly modern Macintosh, though arguably that title belongs to the iMac (released August 15, 1998.). By modern, I refer to the four-handled case design (Known as "El Capitan") intended to emphasize appearance over functionality, and the lack of legacy I/O, specifically serial ports. However the B&W G3 does retain the old ADB connection used primarily for input devices but also for a handful of cameras and modems. More importantly, the B&W models add two USB ports and two Firewire ports. They also have four PCI slots; One 66MHz 32 bit slot used for the video card (An ATI Rage 128 with 16MB and optionally but usually equipped with an MPEG2 decoder daughterboard.) This is the first mac to ship with a video card which uses a HD15 VGA connector rather than the DB15 classic macintosh video connector, though video cards with VGA outputs were available for various older Macs. The three PCI slots which are not 66MHz (instead they are the usual 33MHz) are 64 bit PCI slots, which gives them a significant bandwidth advantage over 32 bit PCI cards. This is quite useful for SCSI host adapters.

Unfortunately Apple badly botched the hardware of the revision 1 Yosemite. Revision 1 systems have an issue which causes data corruption on IDE slave drives and on many aftermarket (non-apple) hard drives, even when installed as the master. This problem occurs during periods of high CPU load while using UDMA Mode 2 (or possible Mode 1) for data access. You can identify the revision of the board by examining the CMD IDE chip which is near the IDE connectors on the board. If the chip says "402" on it, you have a rev 2 motherboard, and your system can safely support aftermarket hard drives and slave drives. In fact, those machines came with a different hard drive bracket which will hold a second drive above the first, with the addition of a different IDE cable. If you do not, you will need to use a tool such as FWB Hard Disk Toolkit or Intech Speed Disk to load a different driver onto your hard disk in order to make the system access the drive using Multi-Word DMA rather than Ultra DMA. (Apple hard drives carry their own drivers for data access.) Apple has acknowledged that this is a problem with their design, but their official response is that aftermarket hard drives are unsupported, so you should use a third party utility to solve the problem. To date, the software which will accomplish this (mentioned just above) costs around US$80. If you are looking at used G3s, it is important to get a revision 2 system unless you like dealing with odd problems like this, or you intend to use SCSI hard drives.

On the plus side, no Macintosh computer released prior to the B&W G3 is easier to work on. While more elderly macs (like the IIci) had a case lid that snapped off, the G3 (And the G4 after it also) has a ring on the side of the case which you pull. The side of the case folds down, and the motherboard and all expansion cards go with it. This allows unparalleled access to the motherboard for changing memory and CPU, and also allows extremely easy access to the optical drive (CD or DVD drive) and Iomega Zip Drive if present. The hard drive or drives sit(s) in a tray on the bottom of the case which is held in with one screw and pops out easily once the ATX-style power connector is removed. The IDE cable for the hard drive is short and inoffensive, and the cable for the optical drive and Zip drive is tucked away so that it never hangs in the way of anything.


Benchmarks indicate that for most tasks, a G3 processor is little slower than a G4 at the same clock rate (speed in MHz.) The G4 shines during "content creation" types of tasks which require a lot of floating point math, such as video or audio encoding and decoding, or rendering 3D graphics. While this means the G3 is a perfectly apt CPU for most applications, such as word processing, desktop publishing, and the like, it is unsuited for video processing, or even video playback. It is impossible to play most MPEG4 content such as DivX and 3ivx on the slower G3 machines.

It is possible to significantly upgrade the processor in these machines thanks to Apple's use of ZIF or "Zero Insertion Force" sockets for mounting the CPU. You can upgrade to a faster G3 processor (up to 1GHz, though 800MHz is more common) or to a G4 processor. Sonnet makes a 1GHz G4 for Beige G3s, but not for Blue & Whites, though they claim at this time to be working on one. Other upgrades are available from Newer Technologies, Phase 5, PowerLogix, and XLR8.


The G3s brought us into a new era of desktop powermacs, characterized by cool cases and easy maintenance. (The G4 cube notwithstanding.) While they do have some flaws they remain a useful system today. It is, however, probably cheaper to buy a used G4 than to upgrade your G3 to have competitive power. In the meantime, the system is useful as a basic desktop machine. It has enough power for day to day tasks, and with Mac OS X 10.2.3 (Jaguar) you can run Apple's new Safari web browser, as well as a number of other well-optimized applications which make the machine seem positively speedy for most purposes. It would probably be a mistake to pay more than about US$400 for a used G3 unless it was "fully loaded" with a high capacity hard drive, at least a CD writer if not a DVD writer, and most especially it should not be a Revision A Beige or Revision 1 B&W machine.


  1. Low End Mac, Power Macintosh G3 (beige). (
  2. Low End Mac, Power Macintosh G3 (Blue and White). (

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