You were a pioneer, someone who rushed out to buy a cool new iMac a few years ago. Your friends were jealous. You were a trendsetter. But now we’re living in the age of the 32x CD-RW drives, digital video cameras, Mac OS X, and the iPod. Yes, times and technologies have changed, and your aging iMac hasn’t been able to keep pace.
But don’t toss out that near relic just yet. Sonnet Technologies has just released the Harmoni G3 Processor Upgrade/FireWire Card Combo for your iMac. For $299, owners of Revisions A through D iMacs (iMac models with processor speeds ranging from 233MHz to 333MHz that shipped with tray-loading CD-ROM drives) can boost their processor speeds to as fast as 500MHz and, unlike previous iMac upgrade products from Sonnet and Newer Technology, gain FireWire compatibility while they’re at it.
Roll Up Your Sleeves
Expansion was clearly not at the top of the Apple engineers’ priority list when they designed these first iMacs. Adding RAM to these computers is enough to make many folks go running and screaming to their local Mac shop. The Harmoni G3 documentation states that if you feel uneasy about installing the upgrade, the company strongly recommends installation by a qualified technician. (A quick look at our article “Upgrade an iMac” [
October 2001] will help you decide if you’re up to the task.)
But if you have previously found yourself elbow deep inside your iMac, then this upgrade shouldn’t be a problem. Sonnet’s documentation is thorough, but the manual’s photos are a little too small and washed out to be truly helpful. That said, the upgrade was still straightforward.
Sum of Its Parts
We installed the Harmoni upgrade on a 333MHz iMac and found speed improvements in every task involving the processor–iMovie rendering, MP3 encoding, and even scrolling up and down in Microsoft Word. However, comparing the upgraded iMac with an iMac that actually shipped with a 500MHz processor demonstrates that an upgrade card still isn’t as good as using a newer iMac, because other system components play into performance.
The slower performance of the upgraded iMac can be attributed to advancements in newer iMacs. These advancements include a faster system bus and the addition of Accelerated Graphics Port (AGP) cards. A slower system bus (66MHz in the Revisions A through D iMacs) means that every bit of data coming from and going to the iMac’s hardware–CPU, graphics processor, hard disk, system memory, and so on–is traveling relatively sluggishly compared to the bus speed found in newer iMacs or the 133MHz bus speed in later Power Mac G4 towers.
The AGP, which appeared after the Revisions A through D iMacs, speeds up the communication lines between the graphics processor and the system memory as compared to the Peripheral Component Interconnect (PCI) bus in older iMacs. Beyond slower performance, the older graphics processors also suffer compatibility issues with OS X and some 3-D applications such as Quake, which does not run in OS X. Apple has not written OS X drivers for these older PCI graphics processors and has not announced plans to do so in the future.
Macworld’s Buying Advice
With a little technical know-how, you can use the Harmoni G3 to increase the processor speed of and start using FireWire peripherals with your older iMac. What it won’t do, though, is turn your iMac into the equivalent of a newer one.
But is it worth it? If you’re a gamer, no. If you’re a Web-surfing Microsoft Office user who’s looking for FireWire compatibility and a nice speed increase for your old iMac, then the Harmoni G3 will get you there.