Nvidia's chips support hardware overlays. Historically CAD software used them, so Nvidia soft-locks the feature in the GeForce drivers to force CAD users to buy Quadro cards for twice the price instead. Their price discrimination means we can't have nice things.
Huh, I've never heard of this. Traditionally, hardware overlays are consumed by the system compositor. Do they have an OpenGL extension to expose it to the app?
I guess it's possible that their overlay support is limited and not fully equivalent to more modern overlays. It's tough to tell for sure from that description. But even if so, the price discrimination aspect may still have stopped them from wanting to implement a more capable feature and expose it in the GeForce drivers.
Ah, this is a classic "RGB overlay", as pioneered by Matrox for the workstation market, which doesn't really mean much, and I assume is fully emulated on a modern chip. Nothing like a modern overlay pipe like you see in the CRTCs on mobile chips.
