In 2004 ATi launched the X800 series that is based on the R4x0 chips. Since competition from nVidia was fierce ATi launched a lot of different models. Some were faster, some weren't. The Radeon X850 Pro was launched in September 2005. Basically it has the same chip as the ATi Radeon X850 XT PE (one of the fastest in the series, chip ID 215RAFCGA11F) but with fewer pixel shaders. I'm guessing these are the chips that didn't have 16 fully functional shaders so they disabled 4 of them and sold it as a lower rated card. A practice that has been done by both ATi/AMD and nVidia to maximize profit. It would be a shame to throw away a chip that can run perfectly with just 12 shaders .

This particular card has a PCB date of early 2006 but a chip date of 18th week 2005. That is months before the official launch which correlates with the story that ATi used chips that didn't cut it for the high end cards.

All in all the X850 Pro was a good performer back in the day. The card still runs fine, however, the fan is a bit noisy due to resonance in it's plastic housing. I guess ATi didn't learn from nVidia's cooling design of the GeForce FX 5800 Ultra . > Read more

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