ATI's R580 graphics chip will appear in three Radeon X1900 configurations: the XT, the XTX and a CrossFire Edition.

So claims Anandtech, citing an "internal ATI presentation". According to the website, the XT and XTX are clocked at 625MHz and 650MHz, respectively, with their DDR memory buffers set to run at 1.45GHz and 1.55GHz, respectively. Both chips support up to 512MB of GDDR 3.

The 90nm R580 core has 48 pixel shaders, as has been predicted in the past. Both the XT and XTX are CrossFire-compatible, and will work with the third board the Radeon X1900 CrossFire Edition master card.

As we reported in December 2005, it has been suggested that ATI will formally announce the R580 on 24 January. Like all X1000-series chips, the X1900 will support DirectX 9 Shader Model 3.0 and ATI's 40-bit video processing system, Avivo.

Anandtech's testing, using "a beta driver from late December" and a sample board mailed from Taiwan, show big frame-rate gains in a range of recent games, particularly when anti-aliasing is enabled. ®