Original URL: http://www.theregister.co.uk/2009/01/16/mac_mini_ion/
Mac mini said to get Ion innards
Courtesy of Tom's Hardware comes the "confirmation " from "an Nvidia partner" that the long-awaited Mac mini upgrade is coming as soon as March, but that it won't be powered by either an Intel Core 2 Duo or a low-power Core i7 .
And no, it won't be an AMD chip.
Instead, according to the rumor du jour, the Mac mini will be based upon Nvidia's Ion platform , and will have at its heart an Intel Atom processor.
The Atom is no speedster - but, then again, the Mac mini hasn't lived its life in the fast lane. The Atom 330 runs at 1.6GHz, has a 1MB L2 cache, and sits on a 533MHz frontside bus (FSB). Compare those specs to those of the current Mac mini and you'll see what we mean: a 1.83GHz or 2GHz Core 2 Duo, 2MB or 4MB L2 cache, and a 667MHz FSB.
But comparing the dual-core Atom 330 to a dual-core Core 2 Duo involves much more than mere speeds and feeds. The architecture of the Core 2 Duo is far more sophisticated than that of the Atom. For one thing - one major thing - the Atom 330 (neé Dual Diamondville) is an in-order processor while the Core 2 Duo uses Out-of-Order (OoO) processing.
Simply put, OoO execution allows a processor to intelligently manage its workflow in a way that prevents precious processing cycles being wasted while instructions wait for data. In-order processors are too dumb to do this, so they can frequently twiddle their digital thumbs while waiting for something to do.
Again, Atom, in-order; Core 2 Duo, OoO. Or to put it another way, Atom, archaic; Core 2 Duo, modern.
That said, the Nvidia 9400M is no dog. What's more, Nvidia's CUDA technology allows the 9400M to unload some processing duties from the Atom in essentially the same way as will the OpenCL technology recently published  by the Khronos Group  and soon to appear in Apple's next operating system, Snow Leopard. That should help.
But would it help enough? Unlikely. CUDA and OpenCL aren't designed to replace a CPU with a GPU; they're designed to offload specifically highly parallel duties such as image and media processing.
The Atom was designed for low-end products such as netbooks, Ultra-Mobile PCs (UMPC ), Mobile Internet Devices (MID ), and the like. Asking it to carry a Mac on its back would be like asking Verne Troyer  to give Yao Ming  a piggyback ride.
Not that it couldn't be done - it's just that it might be as unpleasant an experience as that ride would be for Mr. Troyer and Mr. Ming. ®