From the Lab: Penryn iMacs show promise

Macworld - The 3.06GHz iMac released earlier this week--Apple's first consumer machine to top the 3GHz mark--turned in an impressive performance in Macworld Labs testing, approaching the speed of the standard Mac Pro configuration.

In the rest of our initial tests of the updated iMacs, we found that new 2.4GHz iMac outpaced the 2GHz model it replaces as Apple's entry-level iMac. However, the revamped machine's next-generation Core 2 Duo chip was not enough to push it past the 2.4GHz iMac introduced last August, though there are other hardware factors at play.

The iMacs we've tested are part of the updated iMac line announced Monday by Apple. Externally identical to the aluminum-clad iMacs released in August 2007, these new Macs include a number of under-the-hood improvements, highlighted by the addition of newer Core 2 Duo processors, code-named Penryn. The more energy-efficient Penryn chips also boost the amount of shared L2 cache to 6MB from 4MB in the older iMacs. The new systems also include faster RAM, a speedier frontside bus and--in the case of the 24-inch iMac--an option to include a more powerful graphics card.

Apple offers three standard iMac configurations: two 20-inch models that either run on 2.4GHz or 2.66GHz processors (up from 2GHz and 2.4GHz, respectively); and a 24-inch iMac with a 2.8GHz processor (up from 2.4GHz). Standard hard drive capacities and graphics cards remain unchanged, with the entry-level iMac featuring a 250GB hard drive and ATI HD 2400 GT graphics with 128MB of video RAM. The other two iMacs both feature a 320GB hard drive and ATI HD 2600 Pro graphics with 256MB of video RAM. Despite the changes to the iMac line, pricing remains the same--$1,119 for the entry-level iMac, $1,499 for the mid-range model, and $1,799 for the 24-inch system.

Just as the previous lineup included a faster, optional processor upgrade (in that case, the 2.8GHz Core 2 Extreme) available in a build-to-order configuration, this year's lineup offers a 3.06GHz Core 2 Duo processor, available as a $200 add-on to the standard 24-inch configuration or in a $2,199 build-to-order system that also features an Nvidia GeForce 8800 GS graphics card with 512MB of memory. (When we bought our iMacs at the Apple Store in Palo Alto, Calif., the salesperson referred to this $2,199 system as the "Ultimate" configuration, though additional RAM and hard drive options exist.)

We have all three standard iMacs plus the build-to-order system in the Lab, undergoing testing. And though we are not completely finished testing all of these systems, we wanted to share the results of the two systems we think will be of greatest interest to our readers: the $1,199 2.4GHz iMac and the $2,199, build-to-order 3.06GHz iMac.