Power Macintosh G3/333 Processor Upgrade And Discussion Page - Performance Of Latest G3 & G4 Processor Upgrades



Power Mac MT G3/300 Facts at a Glance

  • G3 (750), 333 MHz
  • Bus Speed: 66 MHz
  • L2 Cache: 1 MB, backside @167 MHz
  • Installed RAM: 128 MB (768 MBMax)
  • RAM Slots: 3, 168-pin SDRAM
  • Min RAM Speed: 10 ns
  • Installed VRAM: 6 MBSGRAM (Max 6 MB)
  • Drive: 9.0 GBUltra/Wide SCSI
  • CD Drive: 24X
  • Removable Drives: Floppy Drive, Zip Drive
  • Networking: 10baseT (other options available)
  • Slots: 3 PCI, 1 COMM
  • Drive Bays: 2 external
  • Additional Ports: ADB, 2 Serial - Printer & Modem , SCSI
  • Supported MacOS: 8.1 - 10
  • Introduced: 8/98
  • Discontinued: 12/98
  • Initial Retail Price: $3,000
  • Current Price
  • Has Personality card with audio/video in/out
  • ATI 3D Rage Pro graphics accelerator
  • Internal Zip drive takes up one drive bay
  • There was a DVD drive option
  • Optional 56K internal modem

PowerMac Upgrade & Troubleshooting
Discussion Forum

The 333 MHz G3 PowerMacs were a follow-on generation to the successful 233 & 266 MHz one. They made their appearance in the summer of 1998 and were discontinued in the last few weeks of the same year.

The machine came in mini-tower form factor and there were both standard models and build-to-order options.

The G3 chip found in the 333 Mhz Tower was a faster version of the PowerPC processor. It's speed was enhanced because the L2 cache resides on a dedicated backside bus running at 167 Mhz, between processor and cache. Previously L2 cache performance was limited by the speed of the main logic board bus which runs at a much slower speed.

The processor and cache reside in on a removable card that fits into a PC type Zif socket making it easy to replace with a faster processor. The main system bus of these G3 machines runs at 66Mhz (the previous pre-G3 Macs ran at 50Mhz). The G3/333 MT comes with 128 MB of SDRAM, expandable to 768 MB using the 3 DIMM sockets.

The graphics controller is the ATI 3D Rage Pro Turbo. The machine came standard with 6 MB SGRAM graphics memory (the maximum), which allows for millions of colors (32-bit) at up to 1280 x 1024 resolution.

There are 3 PCI slots for add-on cards and a proprietary slot for the included AV personality card.

The hard drive is 9 GB Ultra/Wide SCSI on the Tower (using a PCI SCSI card...which uses up one of the slots). The CD ROM is 24x, but there was the option of a DVD drive instead.

The Tower machine has one free 5.23" drive bay (the other is filled with the internal Zip drive) and the machine has anexternal SCSI connector (5Mbytes per second).

The machine's case is easy to get into and the simplicity of the new logic-board design make upgrades a snap.

Below you will find the MacBench 5.0 results for most of the processor upgrades available for this machine.

** Note that MacBench does not take advantage of the Velocity Engine (AltiVec instructions) of the G4. For AltiVec accelerated applications you can see a 1.4 to 4 times performance improvement over the G3, depending on the application and the functions you are trying to perform.


"But I thought that the G4 was so much faster than the G3?" In some cases it is! For G4 Application specific scores - Click Here

MacBench Absolute Scores

Processor Upgrade Card

MacBench 4.0 Processor Score

Power Macintosh G3/333 1110
XLR8 MACh Speed MPe G4/400/200/1MB 1186
XLR8 MACh Velocity MPe Dual G4/400/200/1MB
PowerLogix PowerForce G4Z/400/200/1MB 1243
Sonnet Encore G4/400/200/1MB 1252
XLR8 MACh Speed G3Z/400/200/1MB 1314
XLR8 MACh Speed MPe G4/450/225/1MB 1335
XLR8 MACh Velocity MPe Dual G4/450/225/1MB 1335
PowerLogix PowerForce G4Z/450/225/1MB 1398
XLR8 MACh Speed G3Z/450/225/1MB 1478
XLR8 MACh Speed MPe G4/500/250/1MB 1483
XLR8 MACh Velocity MPe Dual G4/500/250/1MB 1483
XLR8 MACh Speed G3Z/466/233/1MB 1531
Sonnet Encore G4/500/250/1MB 1565
XLR8 MACh Speed G3Z/500/250/1MB 1643
Sonnet Encore G3/500/250/1MB 1679
PowerLogix PowerForce G3Z/500/250/1MB 1680

Internal Links

External Links

More information on the G3/333
  • Processor Card Upgrade Index
  • Graphics Card Upgrades Index
  • Upgrades By Machine
  • Hardware Index
  • Older Machine Benchmark Comparisons
  • Processor Upgrade Cards Manufacturers Links
  • Apple's online specs for the G3/266 Desktop
  • LowEndMac's information page for this machine
  • EveryMac's information page for this machine
  • Apple's online specs for the G3/266 Tower
  • Processor Card Reviews
  • Index of all online Macintosh hardware and software reviews