> there are limited number of SAM460 and X5000 users that can benefit > from R600 (and up) PCIe right now. Mostly OS4 users.
It's certainly a dubious benefit for them if they have to go back to 2D-only support under OS4.
> The only real value in having GCN support is those are the cards that > are usually supplied with X5000 systems and the low end cards have now > transitioned to these gpus.
Availability can be a factor as well. The last cards with TeraScale2 GPUs are R5 210...235 from 2013/2014*, while last cards with GCN1 GPUs are R5/R7 430...450 from 2016.
*Edit: The real last card with TeraScale2 GPU is the R5 310 from 2015.
