Those seeking the ultimate Mac must be prepared for one inevitable disappointment: in a few short months, your computer will no longer be the fastest box on the block. To maintain that bleeding edge, you must either purchase Apple’s latest high-end computer or procure a processor upgrade to accelerate your current Mac.
We examined four such upgrades–XLR8’s Mach Speed G3Z, Newer Technology’s Maxpowr G3-G3 466, Phase 5’s G3 Power Booster, and PowerLogix’s PowerForce G3 ZIF 466/233–designed primarily for the first-generation G3s (the Newer, PowerLogix, and XLR8 cards also work in the blue-and-white G3s). All feature a processor rated at 466MHz and a 1MB backside cache. Given their similar benchmark performance and prices, little separates the cards except the warranties and the manufacturers’ tolerance for having their product overclocked. But at roughly $700 to $850, these upgrades aren’t cheap; only the most demanding users require this kind of power.
Crank It UpThese upgrades fit neatly into the Power Mac G3’s zero insertion force (ZIF) socket. Installing the upgrade requires only that you remove the heat sink clipped atop the Mac’s original processor card, swap the new processor for the old one, and replace the original heat sink (if the upgrade doesn’t include one). The Newer, PowerLogix, and XLR8 cards also require you to install proprietary extensions and control panels for adjusting the speed of the backside cache.
The four upgrade cards are preset to their advertised speed of 466MHz. Your ability to adjust the speed of the cards’ backside cache is somewhat limited–none can be pushed to more than half the speed of the processor.
In addition to adjusting the backside-cache speed, you can also change the clock speed of the processor using DIP switches, jumpers, or adjustment wheels–but only the XLR8 manual encourages you to exceed the rated speed of the processor. The XLR8 Mach Speed G3Z carries four tiny jumpers that you can move to boost the card to 533MHz. A 266MHz G3 refused to boot at this setting but did perform reliably at 500MHz. We were able to obtain 500MHz reliably from the Phase 5 and PowerLogix cards as well.
You can also adjust the Newer Maxpowr G3-G3 466 to a faster clock rate, but it crashed our computer when we set it to 500MHz. Newer states that it won’t be responsible for damage such adjustments cause, and the Phase 5 and PowerLogix warranties indicate that any misuse of their products–and we presume overclocking fits this description–voids the warranty. Only XLR8 seems willing to cover an overclocked upgrade card.
The first PowerLogix upgrade we received was unstable, but its replacement worked perfectly. The other cards operated without a hitch. Although the Newer card scored marginally better in our Graphics test and the PowerLogix upgrade eked out Processor and Disk test scores a few points higher than those of the competing cards, the real-world speed difference between all four cards isn’t noticeable.
With price and performance this close, you’ll base your buying decision largely on warranty and reliability (PowerLogix offers a three-year warranty, Newer and XLR8 guarantee their products for two years, and Phase 5 provides coverage for a single year). Newer Technology consistently produces reliable, well-documented upgrades that are among the fastest in their class; the comparably priced XLR8 card is a solid performer as well, and the company seems willing to let you overclock the processor–a tempting proposition for those living on the bleeding edge.
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August 1999 page: 42