CPU Buying Guide

What is SSE3?

SSE3 is the third iteration of Intel's Streaming SIMD Extensions. Like its predecessors, it's a series of dedicated instructions designed to speed up processor intensive applications such as speech, video editing encryption and gaming. The SSE3 technology was introduced with the first Prescott cores, but it's also available in the Core 2 range of CPUs, and even most of AMD's, thanks to cross-licencing between the two manufacturers.

What is Speedstep?

Speedstep is Intel's power-saving and heat-reduction technology. Originally only available on mobile processors, where energy consumption is a key concern, it's also implemented on a number of Intel's desktop processors. On the desktop it's got a dual role to play, reducing power needs as well as lowering the heat output of some of Intel's hotter processors. Speedstep has undergone several revisions in its lifetime, but the basic operation from an end-user perspective has remained unchanged, as it throttles back processor frequency in response to user needs, so that when your system is idling, it's also not burning itself out.

Mobile Processors

Mobile processor

Intel's current mobile processors don't differ drastically from their desktop counterparts. In fact, the Core micro-architecture was first introduced in notebook computers -- with the Core Duo and Core Solo CPUs -- and then to desktop computers via the Core 2 micro-architecture. Core 2 Duo is now available for both the desktop and mobile platforms, but they do vary slightly in performance.

Mobile Core 2 Duo CPUs are restricted to a top front side bus speed of 800MHz, and 667MHz is far more common, while desktop CPUs have a top front side bus speed of 1333MHz. If you're in the market for a powerful notebook, look for one based on the Core 2 Duo, and if you want to stay ahead of the curve, get one that runs an 800MHz front side bus speed.

The Core 2 Duo for notebooks is also a 64-bit CPU, meaning you can load up 64-bit versions of Vista or Linux, while the Core Duo is only a 32-bit CPU. Both the Core 2 Duo and the Core Duo are dual-core CPUs, but the Core Solo is a single-core CPU. All of Intel's mobile CPUs feature power-saving techniques that shut off various parts of the CPU or slow down the CPU when running on batteries, in order to provide more longevity while on the road.

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