The iMac Core Duo is Apple's first desktop computer to result from the company's partnership with Intel. Combining Intel's new 945GM mobile chipset and the Intel Core Duo processor, the Apple iMac Core Duo marks a significant change for the iconoclastic company, bringing it closer in line with the "Wintel" world. (Boot Camp brings it a couple of steps closer.) More than a perception shift, however, the move to Intel's Core Duo technology allows Apple to keep up with the performance and capabilities of its Windows-based competition. The iMac's biggest trouble is that it's experiencing some of the growing pains inherent to new technologies, but the recent addition of Windows XP-enabling Boot Camp makes up for a lot of lost ground.
Not every software vendor has completed the necessary reprogramming to ensure full performance on the new iMacs, so some applications, Photoshop among them, run significantly slower than on even the older iMac G5s. Fortunately, it's only a matter of time until the software catches up (most major vendors have committed to the transition). And because the new iMac retains and expands on the features of the older models without a price increase (our 2.0GHz, 20-inch review unit costs $1,799 with 1GB of memory; the 1.83GHz, 17-inch model starts at $1,299), the news on this one is mostly good. We do recommend looking into your favorite apps--especially if you use them for work--to see how the compatibility is shaping up before making a purchase. Just want to muck around with iLife and other Apple apps? Then there's no reason to wait.
Software compatibility issues aside, the move to Intel chips is significant to the iMac for reasons beyond the speed increase. First, as its name implies, the Intel Core Duo chip is a dual-core CPU. Not only will you get better multitasking performance, you'll also receive a boost from applications that are multithreaded, or designed to take advantage of two processing cores. This means more efficient, faster computing overall. But beyond the CPU, the Intel 945GM chipset itself introduces some significant new technologies to the iMac Core Duo. The motherboard supports faster 667MHz DDR2 SDRAM, which results in faster access times between the memory and the CPU than with the iMac G5 and its 400MHz DDR memory. As with the iMac G5, the baseline iMac Core Duo ships with a respectable 512MB of memory, but you can add up to 2GB more for an additional $300 at checkout. The stand has RAM-installation instructions printed on the bottom, but bear in mind that opening the case for DIY upgrades is difficult and will probably result in scrapes and scratches.
The iMac Core Duo also has more-advanced 3D graphics capabilities. Apple has upgraded the iMac to ATI's Radeon X1600 3D chip (the 128MB version is standard; 256MB will run you $75 more), which supports all the latest 3D techniques. No one would ever recommend that you buy an Apple computer if gaming is your primary objective, but it's nice to know that if you want to play the occasional game, the iMac Core Duo should be able to keep up, as long as you keep your image quality and performance expectations reasonable.
Along with the core hardware change, the iMac Core Duo is a remarkably complete midrange desktop PC. It boasts the same features as its predecessor, such as an integrated iSight camera and iChat software for videoconferencing and a remote control and the intuitive Front Row suite for playing your digital media files. Both iChat and Front Row have been reprogrammed to run on the Intel chips, as has Apple's Tiger OS X 10.4.4 and the newly announced iLife '06 digital media productivity software, which Apple includes in all new iMacs for free. We're also happy to report that the bundled wireless networking and Bluetooth adapters are also still part of the iMac package, letting you retain the iMac Core Duo's uncluttered aesthetic on your desk.
As we've said, though, the native software support is the crux of the issue for the iMac Core Duo. Thanks to Apple's transparent Rosetta technology, you can run all Apple software on the new iMac. The question is, how fast? As our benchmarks show, the performance difference between software that has been ported to Intel systems, such as iTunes, and those apps that have not been ported, such as Adobe Photoshop and Sorensen Squeeze, is remarkable. But Rosetta is required only when running the Mac OS; with Boot Camp, you can turn the iMac Core Duo (and the other Intel-based Macs) into a dual-boot machine that runs full versions of Mac OS X and Windows XP.
We installed Boot Camp on the iMac and saw nonnative apps, such as Photoshop, run much faster in the Windows environment. We expect this performance delta to shrink or disappear all together once more universal binary apps--nonnative Mac software built for the Intel platform--are released. Still, the transition is far from complete. Though Apple can boast of the hundreds of apps that do run natively on Intel-based Macs, Adobe's universal binary version of its next Creative Suite, which includes Photoshop, is likely more than a year away. Do note, however, that if you are frustrated by Photoshop performance on an iMac currently, you'll need to purchase the Windows version in order to do an end run around Rosetta and operate within Windows. You'll also need to pick up a copy of XP Home or Pro.
On our iTunes test, the iMac Core Duo running Mac OS X was 30 seconds faster than the 2.1GHz iMac G5 at encoding MP3 files. That doesn't translate to the two-to-three times boost Apple CEO Steve Jobs claimed at the iMac Core Duo's introduction; it's more like a third faster (35 percent, actually). Similarly, the iMac Core Duo showed an improvement on our Doom 3 test, posting 16.2 frames per second at 1,024x768, compared to the iMac G5's 11.6. That's not a significant increase, nor is it even a playable frame rate, but please note that Doom 3 is a nonnative application (although a native version has been released since we originally ran this test). Instead, the nonnative speed increase is likely due to the vast leap forward in 3D graphics technology on the iMac Core Duo. And if ATI's newer 3D chip can help Doom 3 running nonnatively, we think it's reasonable to expect that if a native version emerges, you might see an even larger performance gain. Running the iMac Core Duo again in Windows didn't do much to change the picture; our iTunes test took 14 second longer to complete, and Doom 3 frame rates increased but not to a point where you'd call it playable.
Photoshop paints a different picture entirely. First, when in Mac OS X, iMac Core Duo was 81 percent slower than the iMac G5, taking 6 minutes, 30 seconds to run our photo script compared to the iMac G5's 3-minute, 36-second time. Then in Windows, the iMac completed the test in 2 minutes, 49 seconds--less than half the time it took the same system when running the Mac OS X and using Rosetta.