600 MHz G4 Upgrade, by FastMac
Posted: 22-Jul-2004

4 out of 5 Mice

Vendor: FastMac Type: COMMERCIAL

Reviewer: Steve Somerstein Class: HARDWARE

If your old G3 is getting long in the tooth and not quite up to handling the ever larger digital photo and graphic files that seem to become so much more turgid in your formerly speedy computer, maybe it's time for a speed boost. For writing, database chores and handling digitized film scans, my old Blue & White G3 (350 MHz speed) was an admirable trooper, delivering sufficient speed to make all the processing seem almost seamless and quite rapid. It was another matter when I started doing digital photography. Now I passed into another world where waiting for an application's function to complete became the norm rather than exception. Raw image files from my camera took an excruciatingly long time to convert to an editable TIFF format. Following that, the Photoshop editing of the 16-bit TIFF files took 10-20 seconds to complete an image change. All in all it was time for a change.

With the rapid Apple evolution to fast G4s and even faster G5s, I found myself wondering whether and where I should plunk down my dollars. Attractive as the G5s were, I was not happy with Apple's decision to make them OS X exclusively bootable. I wanted the option to choose my OS 9 operating system. I had old but quite serviceable SCSI digital scanners and inkjet printers that might become unusable due to lack of available drivers compatible with OS X.

So it came as a pleasant task to test FastMac's rather inexpensive processor upgrade. For less than a $200 investment, FastMac will breath new life into your Blue & White G3 worthy of a minor religious experience.

FastMac Reviewed

600 MHz G4 Processor Upgrade for 350 MHz Blue & White G3

G4 ZIF Socket Upgrade (500-600 MHz)
The FastMac package came with its G4 CPU upgrade module, a packet of jumper plugs for setting processor speed, and several CDROM operating system installer bundles for both the OS 9.2 and OS X operating systems. The G4 module is almost physically identical to the G3 module in the B&W (see photo below). The disks contained Mac OS 9.2.2, which becomes the "Classic OS", and Mac OS 10.1 with a 10.2 upgrade. In addition, the package included an OS X Developer Tools disk and one FastMac disk containing a 10-page instruction manual in Adobe PDF format and the FastMac G4 Enabler application that unlocks the motherboard support for the FastMac G4 chip.

Note that FastMac included no hard copy of the instruction manual, so I recommend that you print out the ten-page manual before you begin installation. The written and pictorial instructions are quite minimal, but the installation is so simple that they are quite sufficient.

Installing the upgrade ZIF (Zero Insertion Force) module is quite straightforward. It's essentially a one-for-one swap of the main processor CPU plug-in.

The only necessary tools are a screwdriver for prying off the module retainer clip and a needle-nose pliers or tweezers for inserting the board jumpers. The manual's steps are quite well detailed. Here are the main points:

  1. Place FastMac CDROM in drive.
  2. Reboot computer with Blue & White Programmer button pressed.
  3. Click on "Enable G4" application to install.
  4. Shut down computer.
  5. Unplug computer and open computer case.
  6. Remove "Void Warranty If Seal is Removed/Broken" label from atop Jumper Block. Your computer warrantee has already expired anyway. Remove Jumper Block.
  7. Place jumpers into slots as shown in manual.
  8. Remove heat sink over CPU chip by unsnapping clip.
  9. Pull up the CPU release lever and pull the CPU up and off. Set aside.
  10. Place the FastMac XPU upgrade into the ZIF slot.
  11. Push CPU release lever back into place.
  12. Replace heat sink and reattach clip.
  13. Close computer & boot up.

The installation went quite smoothly, and the ZIF CPU module slipped right into place. There are, however, a couple of areas that could merit improvement. The jumpers are relatively easy to install, but they are somewhat of a mild effort to install due to their small size. If FastMac could offer a plug-in jumper block similar to the original Apple Jumper block, the exchange would be a snap.

Surprisingly, in a minor oversight, neither the original CPU nor the FastMac replacement had any thermal paste between the heat sink and the CPU chip. Certainly, if there were some thermally conductive paste supplied, the CPU would run cooler and it might improve its longevity and performance.

OS 9 Benchmark Tests
The benchmark test comparisons were run between the 350 MHz G3 and the 600 MHz G4 using OS 9 and the Speedometer 4.02 application developed by Scott Berfield. Speedometer is a compilation of mathematical and graphical algorithms intended to fully exercise the CPU and graphical processors. The numerical values in the column adjacent to the horizontal bars are the number of iterations of that test that could be performed in one second. Thus, the longer the bar the better the performance. The opposite is true for the color tests located in the bottom section. Here, the number of seconds necessary to perform the test is displayed. Thus, the smaller the number the better.

Speedometer comparisons - G3 under OS 9 vs G4 under OS 9

A summery of the results show that with virtually all Speedometer tests the G4 performance improvement reduces the time to perform the mathematical operation to 60% of that seen with the G3 CPU. The G3 CPU speed compared with that of the G4 CPU gives a ratio of 350 MHz (G3) divided by 600 MHz (G4), or 58%. The ratio of the average of all the G3 to G4 benchmark time measurements is 60%. It can be seen that for most improvements, the CPU clock speed is the deciding value. In addition, it was noted that the Speedometer results were virtually identical whether the OS 9 was run as the booted operating system or in Classic mode within the OS X environment.

The general perception of application speed of operation, file copying, menu pull-down, windows opening and closing is perceptibly faster than with the original G3. The feel of the newly minted G4 is of a far more agile computer.

One of the advantages of installing the G4 upgrade is its ability to run OS X. The supplied OS X, version 10.2, was installed and appeared to operate quite flawlessly.

OS 9 vs OS X Benchmark Tests - Carbonized Photoshop 7
My real world test consisted of running some Photoshop 7 functions both under OS 9 and OS X. Photoshop 7 is a fully "carbonized" application, which means it will run native in either the OS 9 or OS X operating systems. This permits a comparison to be made with the computer running first with the G3 CPU installed (OS 9), then the G4 CPU (OS 9), and finally with the G4 CPU running OS X. The FastMac supplied Apple OS X, version 10.2, was installed on the G4 upgraded computer. FastMac recommends that OS X be installed "after" the installation of the G4 CPU, as Apple installs special needed G4-associated files when the installer recognizes a G4 CPU. The installation went quite smoothly and operated with no apparent problems.

Five different timing tests were run with Photoshop 7 using a 16-bit image file of 95.1 MB: (1) Application launch, (2) Opening a 95.1 MB 16-bit image file, (3) Unsharp mask, (4) Gaussian blur, and (5) Rotate image 90-degrees.

Photoshop 7 speed tests

The comparison results are displayed in the above bar chart. Duration times in seconds for each Photoshop test operation are given next to the bars, with the shorter the bar the faster the time. For ease of comparison, the last column shows each performance measurement as a percentage of the baseline G3 (100%) specific operation performance time. The practical results from Photoshop show that the measured improvement going from a 350 MHz G3 to a 600 MHz G4, depending on the specific Photoshop operation, gives a moderate 12% to 24% time decrease under OS 9. On the other hand, things improve even further when using OS X, with the performance time decreasing by 33% to 68%, depending on the specific operation.

The FastMac CPU upgrade module is an easy path for upgrading a G3 CPU to a G4 with a simple, well-documented installation process of CPU exchange. The G4 upgrade achieves a reasonable and welcome performance increase for a moderate cost. There were a few issues with the installation, such as the lack of thermal paste and no integrated jumper block. Still, this is a great time to upgrade your slowpoke G3. It provides a substantial speed increase, allows you to run OS X, and all without a significant investment in a new G4 or G5. The FastMac G4 upgrade is an excellent choice to rejuvenate your old computer at a very nominal cost.


  • Fast performance for the dollar
  • Relatively simple installation
  • Excellent speed improvement with zippy feel
  • Let's you run OS X (and includes OS X CD)


  • No integrated jumper block (individual jumpers must be installed manually)
  • No thermal paste supplied
  • Moderate speed improvement with OS 9 in Photoshop tests
  • Does not comes with a printed manual (must be printed from PDF)

Overall Rating

4 out of 5 Mice