ATI is launching today their new series of graphic chips based on a new architecture, which we will be explaining its main features in this article. This new series has basically three families, each one for a distinct market segment: Radeon X1300 for the entry-level market, Radeon X1600 for the mid-range market and Radeon X1800 for the high-end market. In each series there are several models being launched and we will explain each one of them on the following pages.
For now, let’s summarize what’s new on Radeon X1000 series:
Shader 3.0 model (i.e. DirectX 9.0c – at last).
Ring bus memory controller on Radeon X1800 and X1600 series.
64-bit High Dynamic Range (HDR) with anti-aliasing at the same time.
New anti-aliasing (adaptive anti-aliasing) and anisotropic filter (high quality anisotropic filter a.k.a. HQ AF) modes.
Full time 32-bit floating point precision.
The high-end model Radeon X1800 XT can achieve a floating point performance (i.e. math performance) of 83 Gflops (billion of math calculations per second). It’s interesting to keep in mind that nVidia’s GeForce 7800 GTX has a 165 Gflops performance, but Radeon X850 XT Platinum Edition has a math performance of 66 Gflops and GeForce 6800 Ultra, 54 Gflops.
2D video processing enhancements, called Avivo (competes with PureVideo, which is available on GeForce series 6 and 7 from from nVidia). Basically what both Avivo and PureVideo do is to make 2D video processing (MPEG2 decoding, for example) to be done by the graphics chip instead of the CPU, increasing the performance of your system, since it will free your CPU to be doing something else.
90 nm manufacturing process.
CrossFire support for all models.
ATI will document its architecture, i.e. anyone interested in learning how it works inside will have access.
High Dynamic Range (HDR)
The problem of lightning is that in the real world lights have unlimited lightning, and the human eye has a perception of 14 dB (10^14:1), but the video card using a standard 32-bit integer buffer is only capable of reproducing 2.4 dB (255:1), because it uses only 8 bits to store each video component (R, G, B and alpha).
Radeon X1000 series uses a 64-bit floating point register for HDR, using 16-bit for each video component. It is really interesting to note that GeForce 7 series from nVidia uses a 128-bit floating point register for HDR.
On the other hand, Radeon X1000 series allows the use of HDR and multi sampling anti-aliasing (MSAA) at the same time.
New Anti-Aliasing and Anisotropic Filter Modes
Radeon X1000 series provides a new AA mode, called adaptive AA. On Figure 1 you can see the difference between adaptive AA and standard multi sampling AA (MSAA).
click to enlarge Figure 1: Multi sampling anti-aliasing vs. adaptive anti-aliasing.
As for anisotropic filtering, Radeon X1000 series introduces a new 16-sample high quality mode (16x HQ). This kind of filtering enhances the quality for images that are not on the conventional plan. To better illustrate this feature, remember Star Wars opening titles. As the letters go to the top of the screen, they become fuzzy and hard to read. Anisotropic filtering is used to get a sharper image and to not become fuzzy like in this example. This filtering can be usually configured as the number of samples used on the filtering process. The highest the number of samples, the sharper the game image will be, but the game will be also slower.
