Many Mac users thought they would never see the day when they could turn their three year old Power Mac G4s back into the speed demons they once were, and at a fraction of the cost of buying a new Power Mac. Giga Designs, PowerLogix, and Sonnet have stepped up to meet the growing demand by offering fast G4 processor upgrades at competitive price points. The fastest single processor upgrades that have been announced by the three companies clock in at 1.2 gigahertz and have recently begun shipping to customers.
With three similar products at different costs, Mac users are bound to have questions about their choices. And choice is a good thing! In this article, each upgrade will be run though the standard suite of gaming benchmarks and various aspects of price versus performance will be examined. I'll also compare the results to the numbers from my previous article to illustrate the performance increase you will get by spending more money.
Specifications and DesignGiga Designs, PowerLogix, and Sonnet were kind enough to provide evaluation units of their 1.2 gigahertz CPU upgrades. All three upgrades are compatible with AGP-equipped Power Macs G4s up to the Quicksilver 2002 model and require Mac OS 9.2.1, 9.2.2, and Mac OS X. Below is table of each card's vital specifications.
| ||L2 Cache||L3 Cache||L3 Cache Speed||MSRP||Cube Comp.|
|G-celerator G4/1.25 GHz||256 KB||2 MB DDR||250 MHz||$599||No|
|PowerForce G4 1.2 GHz||256 KB||2 MB SDR||250 MHz||$608||No|
|Encore/ST G4 1.25 GHz||256 KB||2 MB DDR||250 MHz||$670||Yes|
Giga Designs G-celerator 1.25 GHz
Giga Designs' fastest upgrade is based on Motorola's PowerPC 7455A (revision 3.3) processor and runs at 1.250 GHz (100 MHz bus) or 1.266 GHz (133 MHz bus). The bus multiplier must be adjusted via jumpers if your G4 has a 133 MHz bus. Like the 800 MHz and 1 GHz models, the processor is mounted on a piece of blue PCB with approximately the same dimensions as an Apple single processor card and is cooled by a beefy copper heatsink and small fan. Installation consists of removing the stock heatsink and processor, then securing the G-celerator to the CPU connector with three screws.
The included documentation is much improved and now includes an illustrated installation guide, with a sheet detailing the jumper and bus multiplier settings. Giga Designs does not promote overclocking, but if you are the adventurous type (or the type with deep pockets), you can fiddle around with the multiplier settings. For the record, my review sample completed all benchmarks without incident at 1.35 GHz.
Giga Designs offers a 30 day money back guarantee and a three year limited warranty with every G-celerator.
PowerLogix PowerForce G4 Series 233 1.2 GHz
PowerLogix has simplified their product line by consolidating the Series 100 and 133 lines into the Series 233. A heatsink and fan is no longer included with the processor card; you must reuse the original Apple heatsink. The PowerForce G4 Series 233 package contains a processor board which resembles the original Apple processor board, and a tube of thermal paste. Installation involves swapping out the Apple processor for the PowerLogix processor. The installation instructions are not nearly as detailed as Giga Designs' and Sonnet's illustrated step-by-step guides.
Like the G-celerator, the multiplier is set with dip switches in Digital Audio and Quicksilver G4s. The PowerPC 7455A CPU mounted on the processor board is rated for 1.25 GHz, but runs at 1.2 GHz in all machines.
The PowerForce G4 is backed by a 30-day money back guarantee and a two year limited warranty.
Sonnet Encore/ST G4 1.25 GHz
Last, but not least, is the Encore/ST G4. Running at 1.250 GHz (1.266 GHz in Digital Audio and Quicksilver G4s), Sonnet?s processor upgrade requires no configuration whatsoever. After installation, a process similar to that of the PowerForce G4, the bus speed and multiplier are automatically configured. There are no jumpers or dip switches to futz with on this card. A Cube installation kit (purchased separately) for the Encore/ST G4 can turn your G4 Cube into pint-sized supercomputer.
Sonnet guarantees its products with a three year limited warranty.