Power Macintosh G3/300 Processor Upgrade And Discussion Page - Performance Of Latest G3 & G4 Processor Upgrades

6/1/01

The 300 MHz G3 PowerMacs were a follow-on generation to the successful 233 & 266 MHz ones. They made their appearance in the early Spring of 1998 and were discontinued in the first few weeks of 1999.

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

When the G3/300 MT was first released MacAddict pitted it against an 8600/300, a machine with a 604e processor running at 300MHz. They found the G3/300 completed a suite of NortonUtilities tests that gave the G3 a score roughly 42% higher than the 8600. These scores reflect the advantages of the G3 over the 604e chip. The G3 chip found in the 300Mhz desktop model 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 150 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 Macs ran at 50Mhz). The G3/300 DT comes with 32 MB or 64 MB, and the MT with either 64 or 128 MB or SDRAM, expandable to 768 MB using the 3 DIMM sockets (standard profile 128MB DIMMs will not fit in the desktop machine).

The graphics controller is the ATI 3D Rage II+, though later models came with the Rage Pro as standard. The DT machine came standard with 2MB SGRAM graphics memory which allows for millions of colors (32-bit) at up to 832 x 624 resolution. Graphics memory is expandable to 6MB which will allow millions of colors at higher resolutions and faster 3D performance.The MT came standard with 6 MB

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

The hard drive is 6GB EIDE on the Desktop and a 4, dual 4 or 8.0 GB Ultra/Wide SCSI on the Tower (using a PCI SCSI card...which uses up one of the slots). The dual drive option could be configured into a RAID with included software. The CD ROM is 24x.

The Tower machine has one free 5.23" drive bay (the other is filled with the internal Zip drive) and both machines have external SCSI connectors (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.


Power Mac DT G3/300 Facts at a Glance

  • G3 (750), 300 MHz
  • Bus Speed: 66 MHz
  • L2 Cache: 1 MB, backside @150 MHz
  • Installed RAM: 32, 64 MB (768 MBMax)
  • RAM Slots: 3, 168-pin SDRAM
  • Min RAM Speed: 10 ns
  • Installed VRAM: 2 MBSGRAM (Max 6 MB)
  • Drive: 6 GB EIDE
  • CD Drive: 24X
  • Removable Drives: Floppy Drive, Zip Drive
  • Networking: 10baseT
  • Slots: 3 PCI, 1 COMM
  • Drive Bays: 1 (DT) external
  • Additional Ports: ADB, 2 Serial - Printer & Modem (modem port deactivated by Personality Card), SCSI
  • Supported MacOS: 8.0 - 10
  • Introduced: 3/98
  • Discontinued: 12/98
  • Initial Retail Price: $2,750
  • Current Price
Notes:
  • Has Personality card with 16-Bit audio in/out
  • ATI 3D RAGE II+ or Rage Pro graphics accelerator
  • Desktop model requires low-profile memory modules
  • Internal Zip drive takes up drive bay
  • There was a DVD drive option
  • Optional 56K internal modem

     


Power Mac MT G3/300 Facts at a Glance

  • G3 (750), 300 MHz
  • Bus Speed: 66 MHz
  • L2 Cache: 1 MB, backside @150 MHz
  • Installed RAM: 64, 128 MB (768 MBMax)
  • RAM Slots: 3, 168-pin SDRAM
  • Min RAM Speed: 10 ns
  • Installed VRAM: 6 MBSGRAM (Max 6 MB)
  • Drive: 4, dual 4 or 8.0 GBUltra/Wide SCSI
  • CD Drive: 24X
  • Removable Drives: Floppy Drive, Zip Drive
  • Networking: 10baseT
  • Slots: 3 PCI, 1 COMM
  • Drive Bays: 1 (DT) 2 (Tower) external
  • Additional Ports: ADB, 2 Serial - Printer & Modem , SCSI
  • Supported MacOS: 8.0 - 10
  • Introduced: 3/98
  • Discontinued: 12/98
  • Initial Retail Price: $3,400 - $4,600
  • Current Price
Notes:
  • Has Personality card with audio/video in/out
  • ATI 3D RAGE II+ or 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

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 G3/300 1000
XLR8 MACh Speed MPe G4/400/200/1MB 1186
XLR8 MACh Velocity MPe Dual G4/400/200/1MB
1186
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 G3/300
  • Processor Card Upgrade Index
  • Graphics Card Upgrades Index
  • Upgrades By Machine
  • Hardware Index
  • Comparison of Processor Chip Speeds
  • 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
  • Online reviews of this machine
  • Index of all online Macintosh hardware and software reviews
  •