The smart money says that most other articles on the launch of ATI Radeon X1900 XT and XTX - aka the R580 - will start with chatter about R5xx being late. It's a valid way to kick off the copy on a new ATI high-end GPU product. The delays in getting the silicon into a shipping state - mostly due to a problem in the wafer production that was out of ATI's hands - means that R580 and its associated SKUs are presented barely three months after the R520...

Generally, the major graphics chips companies want to wait at least two quarters before debuting a significantly new high end product, lest they risk of pissing off the early adopters of the previous generation, not to mention the board partners, who have to sell the things. At the first sniff of something new just around the corner, the knowledgeable crowd with the cash to drop on the flagship part will hold off spending.

The chip companies make no secret of the fact they make huge margins on the high end, almost boutique parts. So while they'll still sell the chips eventually - or at least they cross their collective appendages that they will - they'll do so at a much lower price. First-run silicon is an expensive business, especially when the chip is comparatively big. So they want the Big Pockets£¦#8482; to splash out - and do so as early as possible.

All that combines to make the timing of the introduction of R580 and the first two SKUs it powers interesting. ATI and its board partners will tell you the X1800 XT, and especially X1800 XL, have sold strongly since their release. We've no doubt they have. But again, good money says there's bound to have been a tail-off in XT sales in recent weeks as information and rumours on R580 have begun to flow.

Things are what they are, though, and we'd rather not dwell too much on the business and industry side of things during a technical evaluation of a new pixel pusher. And what a pixel pusher R580 seems to be. There are significant differences in how the R580 goes about the business of data processing, compared to the R520. Be under no illusions - the R580 is no simple R520 speed bump