default, opengl and cairo -- what are these?

[janoc]

They are not optimized for gaming for the simple reason there are virtually no games using OpenGL. There is nothing to optimize for. The fact they are intentionally truncated on gaming cards so the pro cards with the same hardware could sell at ridiculous prices is another case.

That's completely wrong. First of all, there are plenty of PC games using OpenGL, basically any cross-platform game running on Mac/Linux will have at least OpenGL backend if it is not written for OpenGL only. All major game engines - Unreal, Unity3D, CryEngine (+ many others) have first class support for OpenGL. Direct3D is available only on Windows and XBox, OpenGL (and OpenGL ES) run almost everywhere.

All mobile platforms (Android, iOS, Blackberry) and non-Microsoft consoles (Sony Playstation 3/4, Nintendo Wiis, Valve's SteamMachine, Ouya ...) use OpenGL ES variants.

All in all, I would dare to say that there are actually more games being released for OpenGL than Direct3D today if you count all the mobile and console platforms too.

Now concerning driver optimization, there the situation is a bit more complex. It is common that the GPU and driver vendors have engineers working with the big game studios to add an "optimization" for the particular game to their drivers - that's why there are, for example, so frequent updates to the Windows Nvidia driver and why it is a 300MB download. Most of the package are these game-specific hacks and there is nothing really changed in the actual driver functionality.

The OpenGL drivers are not "truncated" or crippled, but some vendors do release poor quality drivers because the pro markets or non-Windows markets are not their priority (AMD/Ati, some Intel ...). However, AMD/Ati is not known for their driver quality in general, so it gets only exacerbated with OpenGL.

On the other hand, Nvidia's OpenGL drivers are performing the same between Linux/Windows and on par with Direct3D, even on consumer hardware. What you get extra when you buy a Quadro is a different optimization - such as that the driver will not silently drop frames when the application is running faster than the vsync rate. That is not a problem for a game running on a GeForce and it makes the application run smoother because the GPU doesn't need to stall the rendering pipeline when too many frames are pre-rendered. However, on a Quadro where one could be using e.g. active stereoscopy (a major reason people buy the $5k Quadros for and not available on GeForces) that would cause horrible issues with the stereo glasses going out of sync. So the Quadro driver doesn't drop frames and handles vsync differently. Also the driver is more optimized towards things likes pushing millions of lines and raw triangles/quads to the GPU (something that games don't do to such extent) instead of gigabytes of textures and complicated shaders (which CAD applications almost never use).