Conclusions
Like the G80 on which it's based, the G84 GPU is a formidable piece of technology. The G80's unified shader architecture has scaled down quite gracefully to this welterweight GPU, bringing with it the higher image quality, efficient performance per die area and per watt, and DirectX 10-class features of its much larger sibling.

As a result, the GeForce 8600 GT is without question a nice advance over the two incumbent offerings in its price class, the GeForce 7600 GT and Radeon X1650 XT. The 8600 GT we tested is a hopped-up version from XFX that's clocked somewhat higher than stock and lists for $169. Nevertheless, this card so decisively outperformed the two DX9 cards that there's no doubt the stock-clocked version of the 8600 GT is the best option at $149. This is the kind of progress we like seeing from one generation to the next in the GPU arena, and Nvidia has delivered once again.

That said, the GeForce 8600 GTS faces much stiffer competition in the form of the GeForce 7900 GS and, especially, the Radeon X1950 Pro. The GeForce 8600 GTS is a very good product, but it's fighting above its natural weight class when it takes on the these competitors, both of which have 256-bit paths to memory. The 8600 GTS variant we tested did largely hold its own against the Radeon X1950 Pro in terms of performance, even scoring clear victories in S.T.A.L.K.E.R. and 3DMark06, but the X1950 Pro had an edge overall. That's true even though we used the "overclocked in the box" version of the 8600 GTS from XFX, a card that lists for $239. The Radeon X1950 Pro can be had for around $179 at online vendors if you shop around.

Of course, the X1950 Pro isn't DirectX 10 compliant, and once DX10 apps arrive in force, DX9 cards may begin to feel old very quickly. DX10 is a clean break from the past, and if you want to run DX10 apps, you'll need to have a card that's compliant. But one doesn't wish to be held hostage to the DX10 conversion, forced to cough up more money and to sacrifice DX9 performance in order to get into the club. That's what the Radeon X1950 Pro versus GeForce 8600 GTS tradeoff feels like right now, which is unfortunate.

Nvidia itself offers a way out of this dilemma in the form of the GeForce 8800 GTS 320MB, a vastly more powerful graphics card that costs only 60 bucks more than the XFX GeForce 8600 GTS we tested. Pay the extra 60 bucks, fer goshsakes. You'll be getting a much better value.

Of course, the GeForce 8600 GTS needs nothing more than a price cut to make it more compelling. I wouldn't be surprised to see that happen fairly soon, like when AMD's new mid-range DX10 offerings arrive.