Lab Tested: 21.5- and 27-inch Core I3 IMacs/3.2GHz

With Apple's recent update of the iMac line, all new models now feature discrete graphic subsystems and Intel Core i3 and Core i5 processors. The two systems in this report are a step up from the $1199 21.5-inch 3.06GHz Core i3 iMac we tested on Wednesday. These two new systems use 3.2GHz Core i3 processors and have 1TB hard drives (up from 500GB on the new entry-level iMac) and the same 4GB of 1333MHz DDR3 SDRAM standard in all of the new iMacs. The 21.5-inch version is $1499, while the 27-inch version is $1699.Using our overall system performance test suite, Speedmark 6, we found that the new 3.2GHz Core i3 iMacs, with scores of 188 for the 27-inch model and 190 for the 21.5-inch model, were 6 and 7 percent faster, respectively, than the entry-level 21.5-inch 3.06GHz Core i3 iMac.That performance gap would be even smaller if we were to ignore the Handbrake 0.9.3 test, which was unusually slow on the 3.06GHz Core i3 iMac. We are doing some further testing with a newer version of the application (which was released just after Speedmark 6's debut). The 3.06GHz Core i3 iMac we tested is using a HL (Hitachi-LG) optical drive, while the 3.2GHz models are using Pioneer optical drives. We're also running additional tests with encoded files already ripped to the hard drive to eliminate any role that the optical drives may be playing in this performance peculiarity and hope to report on those findings tomorrow.Both of the new 3.2GHz Core i3 iMacs posted Speedmark scores 16 percent faster than the 3.06 Core 2 Duo systems they replace, not bad for systems with identical price tags. The new systems showed marked improvement over their predecessors in many of our tests, including CineBench (28 percent), iTunes encode (22 percent), iMovie import (25 percent). The only test where an older Core 2 Duo bested the new crop was in our test of unzipping an archive in the Finder, with the older 27-inch iMac finishing the test 5 seconds faster than the newer 27-inch Core i3 iMac.Comparing the new to last year's top of the line iMac, a quad-core 27-inch model with 2.66GHz Core i5 processors, we found the older $1999 model to be 10 and 11 percent faster over all than the new 3.2GHz 21.5 and 27-inch models, respectively. The older quad-core system was 26 percent faster in our Cinebench test and 55 percent faster in our MathematicaMark test. Compressor, too, benefitted from the four cores, with about an 18 percent faster time.We're expecting our new 27-inch quad-core 2.8GHz Core i5 iMac tomorrow, so results should post soon. We're also working on full reviews of all the new iMacs, and we'll post those (with mouse ratings) as soon as possible.James Galbraith is Macworld's lab director.YAHOO! YOUTUBE ZENITH