Yokemate of Keyboards
Posts: 4976 from 2009/1/28
From: Delaware, USA
> AGP variants require a bridge chip, and that hasn't worked well with the R500 card.
> So, it isn't an artificial restriction, supporting AGP variants requires extra work.
I'm not sure how to conclude the requirement of extra work just from the fact that the faster AGP transfers don't work with the AGP variants. So yes, their bandwidth is lower than it could be, but where does the extra work come from for supporting the AGP variants?
The reason the transfer rate is basically 1X is that it has to go across the bridge chip, and Mark does not have documentation of how that chip works.
But it isn't transparent, it needs to be programmed, so whatever work around he managed to implement with the R500 driver did require additional work.