Just a curiosity question really but one that I can't seem to find a good answer for (or at least one that satisfactorily scratches this particular curiosity itch ).
In all the hardware review sites that discuss AMD's 800 series chipsets I've seen the same block diagram over and over again that shows the SB850 with a single PATA channel coming off the southbridge. TR has two diagrams showing this, one for when the 890GX debuted and another for the 890FX pseudo round-up:
But all the boards that I've seen and the reviews that I've read (mostly 890FX boards) seem to be using an auxiliary third-party chip for the PATA controller (if they have a PATA port at all).
So, I'm wanting to know: if the SB850 does actually have a single port PATA controller, why aren't motherboard makers using it? Are the chipset block diagrams out of date and AMD has actually removed the PATA controller from the SB850 as Intel did a few Southbridges ago? Or is there some issue with the SB850's PATA controller that prevents board makers from using it (like the USB problems on AMD's early 768 southbridges)?
Or, maybe a simpler question: has anyone found a board that's using the SB850 that has a PATA port that is being controlled by the SB850 rather than a third party controller? But the more interesting question is if no manufacturers are doing this, why?