Last week, Apple announced two notable changes to the iMac line, available now. First, all iMacs now use Intel's new 64-bit Core 2 Duo processor, which Apple claims can deliver up to 50 percent faster performance than previous Core Duo processors. However, in testing done by PC World on PC laptops, the Core 2 Duo chip improved performance by only 5 to 10 percent over identically configured laptops with the older Core Duo chip; Macworld's benchmarks rated a 10 percent improvement. My guess is that the new iMacs with the Core 2 Duo will be faster, perhaps noticeably so in some tasks, but not so much that it would make sense to upgrade from an existing Core Duo-based iMac to a new Core 2 Duo-based model.
However, the second notable change in the iMac line may be sufficiently compelling to cause even a recent iMac purchaser to consider trading up to a new model. That's because the top-of-the-line iMac now comes with a built-in 24-inch widescreen display running at 1920 by 1200 pixels (compare that with 1440 by 900 for the 17-inch display and 1680 by 1050 for the 20-inch model). The 24-inch display also offers a wider viewing angle than the smaller displays, is brighter, and provides a higher contrast ratio than the 17-inch display (though slightly lower than the 20-inch display).
Interestingly, there are a number of other differences between the 24-inch iMac and the smaller models besides some added size and weight. The 24-inch iMac uses a faster Nvidia GeForce 7300 GT graphics processor (or an optional Nvidia GeForce 7600 GT) in favor of the Intel GMA 950 (in the 1.83 GHz 17-inch iMac) or the ATI Radeon X1600 (in the 2.0 GHz 17-inch iMac and the 20-inch iMac). Instead of a pair of FireWire 400 ports, the 24-inch iMac features one FireWire 400 port and one FireWire 800 port. It also doubles the power of its internal digital amplifier from 12 watts in the 17- and 20-inch iMacs to 24 watts.
A Plethora of Possibilities -- Configuring an iMac is a bit more confusing than in the past, since the low-end 1.83 GHz 17-inch iMac, priced at only $1,000, can be configured only with more RAM (512 MB standard, up to 2 GB), with an Apple Remote, and with a modem. It comes standard with a Combo drive, a 160 GB hard drive, Intel GMA 950 graphics processor, and AirPort Extreme, but not Bluetooth. This basic configuration was introduced in July 2006 for education buyers (see "New iMac Replaces eMac for Education", 10-Jul-06); it's now available to anyone (and it still costs $900 for educational customers).
The 2.0 GHz 17-inch iMac ($1,200) can be upgraded to a 2.16 GHz Core 2 Duo processor and comes with a 160 GB hard drive, upgradable to 500 GB. In contrast, the 20-inch ($1,500) and 24-inch ($2,000) iMacs both come with a 2.16 GHz Core 2 Duo processor, upgradable to 2.33 GHz, and they both have 250 GB hard drives, with 500 GB options. All three of these models come with an 8x double-layer SuperDrive, 1 GB of RAM (upgradable to 3 GB), and built-in AirPort Extreme and Bluetooth 2.0.
Standard equipment for all iMac models includes a built-in iSight camera, three USB 2.0 ports, two FireWire ports, Gigabit Ethernet, mini-DVI out, built-in stereo speakers, a built-in microphone, optical digital audio in/out jacks, Mac OS X 10.4 Tiger, and iLife '06.
Mac mini Speed Bumped -- Although the also-updated Mac mini doesn't share the iMac's switch to the Core 2 Duo chip, Apple has speed-bumped the low-end Mac, dropping the Intel Core Solo processor entirely while keeping prices at their previous level. The $800 Mac mini moves from a 1.66 GHz Core Duo processor to a 1.83 GHz Core Duo processor, and the $600 model drops its 1.5 GHz Core Solo processor in favor of a dual-core 1.66 GHz Core Duo processor. All other specs remain the same.