The new low-end iMac -- one of several models released this week -- displays some significant performance boosts over its predecessor, tests show. The latest version switches from a 3.06GHz Core 2 Duo CPU to a Core i3 processor of the same clock speed. Graphics are now handled by a dedicated ATI Radeon HD 4670 chipset with 256MB of onboard memory, instead of NVIDIA's integrated GeForce 9400M; system RAM has been upgraded in speed from 1,066MHz to 1,333MHz.
