Conclusions
One thing is abundantly clear about Nvidia's Ion reference design: it's much, much better than the 945G-series chipset and GMA 950 graphics that Intel typically pairs with the Atom processor. But that's sort of like saying Jessica Alba is hotter than Susan Sarandon. The real question is whether the Ion platform actually makes for a more capable system without spoiling the Atom processor's existing appeal. And the answer is yes.

Nvidia maintains that Ion-based systems shouldn't cost significantly more than those based on Intel's current Atom platform. Considering that the GeForce 9400 chipset has significantly more going on under the hood, its value proposition looks pretty solid. The chipset's power draw is reasonable, too, even if it's a little higher than the Intel alternative. Our reference system drew just 25W from a wall socket while playing back Blu-ray movies, which is very impressive indeed.

So what of the Ion platform's ability to extend Atom's capabilities into new territory? Gaming is one area where there's certainly room for improvement, if only because the GMA 950's limited compatibility and atrocious performance set the bar so low. However, an Atom processor, even with two cores, is still ill-equipped to handle recent and even slightly older games. Sure, you'll be able to find "casual" titles that run with acceptable performance on an Ion box, but don't expect every game off the shelf to run smoothly, even at low resolutions and in-game detail levels—the graphics chip isn't the bottleneck. At least with a GeForce ensuring broad compatibility, you'll be able to dive into the bargain bin for older titles that demand less from the CPU.

We already knew the Atom didn't have much game, so for us the Ion platform's real potential has always rested on its multimedia prowess. The chipset's ability to feed both video and multi-channel LPCM audio over an HDMI output is perfect for home theater PC applications, and support for DisplayPort output ensures future compatibility with new monitors. Nvidia's PureVideo HD decoding engine is also a small wonder, allowing for the smooth playback of most Blu-ray movies in systems with even a single-core Atom CPU. However, PureVideo's prowess isn't universal; there seems to be a definite issue with 1080i content encoded with the VC-1 codec, which admittedly makes up a small slice of the high-definition video market. If I were building a nettop tasked with HD playback, I'd want it to have dual memory channels and a dual-core Atom, just to be on the safe side. But I'm paranoid like that.

What's particularly compelling about Nvidia's Ion reference system is that, despite its few shortcomings, it's still far more capable than Intel's existing Atom platform. An Ion-based system might not play back every single Blu-ray title perfectly or run every game at acceptable frame rates, but you can't do either on a 945G-based Atom box, ever. So if you've already settled on an Atom-based rig, you definitely want one with a GeForce 9400 chipset.

Except you can't buy Ion-based systems just yet. In fact, we haven't heard of any in development. I wouldn't be surprised to see the platform pop up in the next Mac mini refresh, but we shouldn't have to wait for Cupertino to catch on. The market deserves a better Atom platform, and Ion is it.