PowerLogix PowerForce Dual G4 1GHz Series 100 review

Numerous upgrade companies have fallen by the wayside over the last few years, as internal improvements to the Mac have made their job difficult.

PowerLogix has stuck it out, and its latest series of products, the PowerForce G4 series, is designed to refresh older Power Macs and enable them to run at today's speeds, without you having to buy a whole new system. We tested the PowerLogix PowerForce Dual G4 1GHz product, which, as its name suggests, replaces your Power Mac's existing CPU with two 1GHz chips, the same as in Apple's mid-range Power Mac.

Note that, because of internal changes to the Mac's architecture, this product will only work in a very specific set of Macs. It's designed for the second generation of Power Mac G4s, the first to use AGP graphics cards, or the subsequent family of Power Macs, which were the first to ship with Gigabit Ethernet built in.

All of these machines were originally sold with either single or dual processors running at between 350MHz and 500MHz. On some early single-processor models the upgrade won't work, as the motherboard doesn't support multiple processors. PowerLogix has a utility on its Web site (www.powerlogix.co.uk) enabling you to check if your Mac is compatible.

Doing the double

On the face of it, this product should at least double the performance of your machine, and if you own a single-processor 350MHz Power Mac G4, the benefit will be significantly higher. We tested it in the MacUser Labs benchmark machine, which is a 450MHz dual-processor Power Mac G4.

The PowerForce G4 is provided with detailed instructions, which it needs, as installation is not as simple as it used to be in the days of daughtercard and ZIF architectures. Handily, the manual is a single sheet, so you won't need to flick through pages to find the information you need with one hand while you hold your motherboard together with the other.

The first step is to remove the old processor card by unlatching the heatsink retainers and unscrewing the card from the motherboard. The PowerLogix card then fits into the same place. The card already has the heatsink attached, and be warned, it's huge. It looks like something out of the engine compartment of a Formula One car, and it's very heavy.

The instructions show you how to make sure it's properly aligned so you don't damage either the card or the motherboard. A useful tip: make sure you have a long screwdriver. The heatsink on the PowerLogix card is so thick that our small screwdriver couldn't reach the screw to attach the card to the motherboard.

As if the heatsink wasn't big enough to start with, you'll then need to attach the supplied fan to the top of it, and connect this to a spare internal drive power supply. That should be all there is to installing the board, although at first our Mac wouldn't start up. The troubleshooting section of the instructions suggests a number of possible remedies, including pressing the reset switch on the motherboard, resetting the PRAM and making sure your Mac's firmware is up-to-date.

On firm ground

The latter turned out to be the problem in our case, and once the firmware update had been downloaded and installed, which required a reboot into Mac OS 9, the machine started up fine. It's worth checking this before you start the installation, otherwise you'll have to reinstall your original card if you later have a problem.

Once the card has been installed, all you need to do is start up your Mac and reap the benefits of a faster system. The improvement was immediately noticeable, from basic operation of the operating system to opening applications and so on.