Confusing is the most common reaction when looking at nVidia's 8800 product line. Since 8800 is still the best GPU available on today's market, there's no need to emphasize that. This review will focus primary on the difference between each lines and how to make an intelligent decision.
The complexity of the 8800 product line leads to the two most frequent questions from customers; A: which card is the best option? and, if you own 8800 already, B: should I upgrade? Below is a list of 8800 product lines ordered by of performance from 8800GTX and below and most recent price available in the market.
8800 GTX $400+
8800 GTS 512mb A3 $285
8800 GTS 512mb AR $250
8800 GT 512mb $200
8800 GTS 640mb $300
The GTS 640mb was the second best graphic card last year and the best card in dollar/performance perspective. nVidia, than, released GT 512mb which marketed around $200 early this year. If you heard people saying that GT is faster than old GTS, you better believe that. Even with less aggressive look (single slot for GT), cheaper price, and reduced amount of memory, GT outperformed old GTS roughly by 26%. It is simply because the architecture of the GPU. The GT is based on G92 while old GTS and GTX are based on G80. The price though doesn't make any sense in terms of reflecting that and I believed nVidia intentionally leaves that to the market to decide the fate of old GTS. Keep in mind that Graphic card is the most competitive component in the PC industry. In order to penetrate and gain market share, nVidia has to have an aggressive plan including killing its own product.
The differences between new GTS and GT are subtle. Some report shows that the new GTS can even outperform GTX in several games (remember that's the result of new architecture of G90.) In general, it is very close but not as good as GTX. Why not GTX? When you factor in the retail price, you'll know why. You won't get a GTX lower than $400 but you can easily find a GT for $200 and an AR version GTS for $250. A gap of $200 I believe is sufficed to eliminate the GTX decision. So scope really narrows down to GT vs. new GTS.
New GTS outperforms in almost every aspects (10%-15% gain)
New GTS looks as aggressive as old GTS
GT is cheaper than GTS
GT has best dollar/performance ratio
For price/performance perspective, GT is a no brainier. But I have to tell you that GTS 512mb is an extremely nice looking card and I believe most hardcore gamers do pay attention to "the look" of each component in their rigs. In another word, if you can justify $50 - $85 for more performance (not too much) and sexier looking, get a GTS. If not, than GT.
Finally, for people who have 8800 already, is it time to upgrade?
For GT owners, I already addressed the $50 - $85 dilemma above so I won't repeat. For old GTS owners though, they have a lot to think. Many online reviews tell you that it's not worth to upgrade. It is true when you look at the price and trouble you have to go through. However, old GTS is still holding $300 + line today. It means that the market still hasn't reflected the GT factor. When it does, in theory, the old GTS price will drop below $200 or nVidia will simply discontinue the line. Whatever the outcome is, you're old GTS is losing its value faster than GT and new GTS. To offset that, the best way I'd suggest is to sell your old GTS and replace with a new one. The new GTS will continue to hold the value or, I should say, it will bleed way slower than old GTS and I believe that's what the only thing that a costumer could ask for right?
But don't anticipate you'll see a huge gain if you do so. I ran a 3DMark on both cards and the new one gains only couple hundreds. But I was able to run Crysis in high setting and 16X AA in new GTS. It is also good to know that the new GTS consumes less power than old GTS. Again, that's the result of new GPU architecture. The swap is only an action that makes your investment depreciate slower. And remember that, once market has figured out the price, you won't have the advantage to swap those two cards.