According to the latest rumours the X800XT card from ATi will be delayed for about two weeks. The card will now probably be launched in June, and not in mid-May. This card is based on the same architecture as the X800PRO (R420). The XT stands for faster clock speed and four extra pipelines. There is also a X880XT coming, this card is based on the R423.
The Radeon X800XT will be a 16 pipeline card since ATI learned how to make those few pipelines that were corrupted to work now. We reported last year that the R420 is a 12 pipline design with four broken pipelines. We still don't have any idea what went wrong with them but it seems that in certain cases they actually can enable all the pipes. X800XT will be clocked at a rather impressive 500MHz and with 1000MHz memory. We are talking about the same core - it's 96 bit precision and PS 2.0 only.
It's clear now that there will be no support from ATI for PS 3.0 and 128 bit precision before R500 in late 2004 or spring next year.