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Quad-core chip makes sense for Apple laptop

Speculation is rife that Apple is readying a MacBook Pro update that will be powered by a new Intel Core "i" series processor.

Brooke Crothers Former CNET contributor
Brooke Crothers writes about mobile computer systems, including laptops, tablets, smartphones: how they define the computing experience and the hardware that makes them tick. He has served as an editor at large at CNET News and a contributing reporter to The New York Times' Bits and Technology sections. His interest in things small began when living in Tokyo in a very small apartment for a very long time.
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Brooke Crothers
2 min read

If the speculation about a new MacBook Pro is on the money, the step up to Intel's quad-core mobile technology would have a profound impact on this vaunted line of Apple laptops.

Is a Core i series Apple laptop on the way
Is a Core i series Apple laptop on the way? Apple

So, why would Apple adopt a Core i processor in a laptop? The short answer is OS X Snow Leopard. The new operating system is designed to be better at wringing more performance out of multicore processors--and the Core i chips pack four cores.

The long answer is the Core "i" chips themselves. The Core i, a.k.a. "Nehalem," is a brand new Intel microarchitecture brimming with performance improvements over the current Core 2 design.

For starters, the recently announced mobile i7-820QM processor integrates a hefty 8MB of cache memory--compared with the 6MB in the fastest Core 2 Duo that Apple currently offers on the MacBook Pro. Generally, the larger the cache memory, the better the performance.

But Intel has done a lot more than just up the transistor count via a larger cache. While the quad-core i7-820QM is rated at 1.73GHz, a single core can be "overclocked" to 3.06 GHz. Intel does this with a technology dubbed Turbo Boost, which speeds up and slows down individual cores to meet processing and power-efficiency needs, respectively.

Need more convincing? The Core i7 also comes with Hyper-Threading, which can double the number of tasks--or threads--a processor can execute. You won't find that in the Core 2 chips.

Digital media creation also gets a boost. Intel claims up to 81 percent faster video encoding.

And the mobile Core i7 is not a power hog--relatively speaking. The i7-820QM is rated at 45 watts, less than a third of the power envelope of the desktop Core i7. With such a powerful processor, heat would be an issue of course but the 45-watt power envelope is manageable.

That said, there are reports that Apple is not bringing out any more products this year. So, along these lines, alternatively, Apple could opt initially for the upcoming "Arrandale" Core i chips--due by the beginning of next year--that are based on a more advanced 32-nanometer manufacturing process. (Current Core i processors use a 45-nanometer process.)

Arrandale integrates graphics silicon into the same chip package as the main processor--a first for Intel. Because of this high level of integration, Arrandale, however, is a dual-core chip.

But probably the closest thing to a rumored MacBook Pro refresh is the iMac, which has the same space-constrained characteristics of a laptop. The quad-core Core i7 in the new iMac "boosts application performance up to 2x over the previous-generation iMac," according to Apple--and that's what consumers can expect with a Core i series laptop.