The newest iMacs are available with Core i5 and Core i7 CPUs and early benchmarks are in. Intel is phasing out the Core 2 Duo chips in favor of the i5 and i7 lines.

In general, the i5 is a single CPU with 4 cores inside it - compared to the Core 2 Duo with 2 cores. The i7 is a single CPU with 4 cores plus hyper-threading. Hyper-threading lets you run two threads simultaneously on each core. So an i5 can run four threads and an i7 can run eight threads simultaneously.

Both the i5 and i7 are able to be used as mobile processors. I sent an email out a while back about a laptop with an i7 inside it.

The CPU benchmarks for the i7 iMac puts it in the same ballpark as the Intel Xeon processors, which are very fast CPUs not suitable for mobile uses. The i5 is about 50% faster then a Core 2 Duo - and that’s with the i5 running at a lower speed. An i7 running at a faster speed then the i5 (but still slower then the Core 2 Duo) is almost twice as fast as a Core 2 Duo.

This puts an i7 iMac in desktop workstation territory - suitable for rendering and professional video processing.

This is all very exciting for geeks, but especially for mobile ones. As the i7 migrates into laptops, the only sticking point left in mobile performance for developers and consultants will be hard drives. Laptop hard drives perform much worse then desktop equivalents. But SSDs (flash-memory hard drives) perform equally well in mobile or desktop platforms. With an i7 and an SSD, a laptop would perform equally well to a desktop in all but one category - graphics.

And even there it’s a pretty good story. Mobile graphics have come a long way. Thanks to the competition between Nvidia and ATI (AMD) and the fact that the market has swung to selling more laptops then desktops, the mobile graphics chips have gotten very good.

It used to be easy to buy a desktop that would outperform a laptop. That’s changing. In the future you’ll have to buy workstation class desktops in order to exceed laptop performance. And that’s good for mobile consultants.