Giga Designs G4 Upgrades

The argument for buying a processor upgrade gets a little weaker each time Apple introduces a new machine. But if you’re not sure you want to forsake your trusty old Mac, an upgrade card will let you throw a smaller overall amount of money at the problem.

We looked at the second generation of upgrades for Power Mac G4s (models with AGP graphics, through the Quicksilver) from Giga Designs: the G-celerator GC1-800-S2, which runs at 800MHz, and the G-celerator GC5-1000-S2, which runs at 1GHz.

To test Giga Designs’ cards, we installed them on our 500MHz Power Mac G4 (AGP graphics) test system and ran the Mac through our Speedmark suite of application-based tests. Installing the upgrades took less than ten minutes; we were able to begin using both cards immediately and found no compatibility issues or glitches.

Though instructions are not included in the documentation, both cards let you overclock the CPU — run the chip beyond its normally rated speed by changing the jumper settings. But we don’t recommend it. Doing so voids your warranty and could be hazardous to the CPU’s long-term health.

There’s no arguing about the allure of a flat-out deal, and at $280, the GC1-800-S2 is one of the lowest-cost 800MHz upgrades available for G4s. It includes 2MB of L3 cache, which you won’t find in the 800MHz iMac, for example. Except for its lower graphics scores (due to the older graphics chips on older machines), the GC1-800’s performance beat that of the iMac.

Likewise, the competitively priced $420 GC5-1000-S2 1GHz G4 upgrade card comes with a full 2MB of L3 cache and turns in benchmark numbers on a par with those of both Sonnet’s and PowerLogix’s 1GHz cards (see “Power Mac Power Boost,” March 2003). To keep the prices of their cards down, Giga Designs does not use DDR memory for their backside caches, as Apple does. Instead, the company opts for less-expensive static RAM. We found only negligible performance differences between the two types of RAM.

Macworld’s Buying Advice

We highly recommend the G-celerator GC1-800-S2, as it’s a good performer with a very tempting price. For the best system performance, you can’t beat buying a new machine. But we can still recommend the G-celerator GC5-1000-S2 for its speedy performance and trouble-free operation.