The GeForce 7900 GTX falls into the same price range as the Radeon X1900 XT, so both these cards are present in the high-end category. But while the Radeon X1900 XTX looks competitive against the GeForce 7900 GTX in the premium class, the Radeon X1900 XT with lower GPU and memory clock rates has no chance against such a formidable opponent.
The trio of less powerful products – the Radeon X1800 XT, Radeon X1900 GT and GeForce 7900 GT – yield most curious results. Having only 16 pixel processors, the Radeon X1800 XT, which belongs to the first generation of top-end Radeon X1000 products, is often ahead of the newer Radeon X1900 GT, which has 36 pixel processors. There is a simple explanation, though: despite the claims of ATI Technologies, texture-processing speed is no less or sometimes even more important in modern games than the pixel shader performance. The Radeon X1800 XT not only has 16 TMUs, but also a higher core clock rate in comparison with the Radeon X1900 GT. This makes it competitive against the GeForce 7900 GT which is equipped with 24 TMUs, but has a much lower core frequency. Moreover, the Radeon X1800 XT has 512 megabytes of onboard memory, which is two times the amount of memory on the GeForce 7900 GT or on the Radeon X1900 GT. This difference may be crucial in some situations, for example in Titan Quest.
There are no great changes when we switch to 1600x1200 resolution, except that the Radeon X1900 GT looks somewhat better against the others. It is especially good at rendering scenes that abound in calculations-heavy pixel shaders like the closed scenes in TES IV: Oblivion.
The GeForce 7900 GTX enjoys an advantage over the Radeon X1900 XT in 1920x1200 resolution. For some unclear reason, the ring-bus memory controller doesn’t help ATI Technologies’ solution. It must be unable to make up for the difference in the memory frequency, 725 (1450) MHz against the opponent’s 800 (1600) MHz. The results of the GeForce 7900 GT are somewhat worse, too, especially in TES IV: Oblivion. Note that the cards’ performance is often not high enough for comfortable play in this resolution.
It’s all clear about what card to choose from the high-end category. The GeForce 7900 GTX is beyond doubt the best choice in the top price range. It is nearly always faster than the Radeon X1900 XT and has best results when you use extreme resolutions along with full-screen antialiasing. Among the cheaper products, you can choose between the GeForce 7900 GT and the Radeon X1800 XT. These two are generally similar in performance, but behave differently from game to game: Nvidia’s card is better in TES IV: Oblivion, but ATI’s one is superior in Titan Quest, for example. An additional argument in favor of the Radeon X1800 XT is its larger amount of memory (if you buy a Radeon X1800 XT 512MB).
The Radeon X1900 GT is only good in games that make wide use of complex math1ematics-rich pixel shaders, like in TES IV: Oblivion and Rise of Nations: Rise of Legends. In other cases this solution suffers from its low fill rate, and the 36 pixel processors of the Radeon X1900 GT most often cannot make up for its having only 12 TMUs.