For example, the Core i7 in this MacBook Pro generally runs at 2.2GHz if all four cores are needed. But with Intel's Turbo Boost technology, if only a couple of cores are needed, those two run at a higher clock speed. In this case, that's 3.3GHz. Four cores at 2.2GHz, two cores at 3.3GHz. That's why an i7 rated at 2.2GHz is actually faster than the 3.06GHz Core 2 Duo processor in my own MacBook Pro.

There's more to these new processors than just clock speeds, however. The biggest advance is that everything is integrated in one place: the processor itself, the Intel integrated graphics, the memory controller and cache. That allows the sum to work faster than the parts.

And Intel's Hyper-Threading technology adds even more speed: It allows two threads of work to run at the same time across four cores, essentially giving you four real processor cores and four virtual processor cores. The computer thinks it has eight cores, even though there are only four.

What's this mean? For day-to-day stuff like Web surfing, text editing and listening to iTunes, not a lot. Web page rendering is still going to be limited by your Internet connection and your browser. But if you're doing something like encoding video or laying down audio tracks, you should see a big gain in speed.

More about performance in a bit. But I will say it's weird to glance at my in the menu bar and see eight "CPUs" sitting up there.