There are currently two ultra-high-performance graphics cards in the RADEON X1000 family: the mighty RADEON X1800 XT 512MB with its sky-high operating frequencies and the less powerful RADEON X1800 XL. Here's a short list of the characteristics of the latter card: like the senior model, the RADEON X1800 XL uses the new-generation R520 chip as the graphics processing unit. The micro-architecture of this future-anticipating GPU was specially developed for very fast execution of complex pixel shaders and our theoretical tests showed that the R520 (the world's first GPU to be manufactured on 0.09-micron tech process, by the way) is really the most efficient at processing complex shaders as well as shaders with dynamic branching (for details see our article called ATI RADEON X1000: Brand-New Graphics Architecture from ATI Explored). ATI's new chip can also work with FSAA and HDR simultaneously and incorporates an advanced video-processor Avivo which provides hardware acceleration for H.264 video decoding. So this GPU is currently the most advanced from the technological standpoint.
The graphics card did well in real-life applications, too. The clock rates of the RADEON X1800 XL are not very high, just 500/500 (1000) MHz for the graphics core and memory, respectively, but the new architecture, particularly the unique ring-bus memory controller, delivered high performance in current games, especially in pixel-shader-heavy ones like Splinter Cell: Chaos Theory, F.E.A.R., Battlefield 2 and others. However, while the RADEON X1800 XT 512MB was the world's fastest graphics card on the day of its announcement (the GeForce 7800 GTX 512 has become the new king since, as you know from our review called NVIDIA GeForce 7800 GTX 512: Faster, Higher, Stronger!), the RADEON X1800 XL could not be called the best in its price category (for details see our review called ATI RADEON X1800 XT and XL Performance: Crushing NVIDIA's 7800?). In some cases it was even inferior to the NVIDIA GeForce 7800 GT where ATI's solution had been traditionally strong, i.e. in FSAA modes, despite the more advanced memory controller with the ring-bus topology. The imperfect Catalyst driver suite was one of the reasons for that discomfiture. Also because of the inefficient and long-criticized OpenGL driver, the new graphics cards from ATI turned to be slow in OpenGL applications like Doom 3, The Chronicles of Riddick, Pacific Fighters, etc.
It is possible that the new version of the driver suite released today (it's now ATI Catalyst 5.12) will help solve the performance-related problems of the RADEON X1800 XL in some games. We took a Sapphire RADEON X1800 XL as the test sample ?this card is going to represent the ATI side today.
