New Intel Core i5 and i7 processors.

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Up to 1.7x faster at the core.

New quad-core Intel Core i5 processors are standard on the new iMac. Choose a 21.5-inch iMac with a 2.5GHz or 2.7GHz quad-core Intel Core i5. Or expand your view with a 27-inch iMac featuring a 2.7GHz or 3.1GHz quad-core Intel Core i5. You can even configure iMac with the fastest quad-core processor available — the Intel Core i7. All models use Intel’s recently refined chipsets. That means the new iMac performs nearly twice as fast as the previous generation,¹ adding a new dimension of speed to everything you do. And since Mac OS X is designed to take advantage of each core, it captures every last bit of performance from the processor.
Turbo Boost 2.0.

Say you’re using a processor-intensive application like Aperture 3 or Final Cut Pro that benefits from extra power. Turbo Boost 2.0 automatically increases the speed of the active cores — up to 3.8GHz. And by shifting core frequency in small increments, Turbo Boost allows the processor to manage performance without sacrificing efficiency. All this takes place behind the scenes, so your work (or play) goes smoother and faster.
Faster single-chip microarchitecture.

Watching a movie, updating your blog, editing photos. Tasks like these require data to travel from place to place. The latest Intel Core architecture puts the processor, cache, memory controller, and graphics engine on a single chip. Since data doesn’t have as far to travel, you get faster performance and greater efficiency.
Integrated memory controller.

With faster access to memory, each core gets right to work on your data, rather than waiting for it to arrive. That’s why Intel Core architecture uses an integrated memory controller to connect fast 1333MHz memory directly to the processor. Together with up to 8MB of shared L3 cache, that helps your applications run at peak performance.