(02-21-2014, 12:36 PM)JMC47 Wrote: D3D11 is better in some games, OpenGL is better in others.
D3D11 is faster in some games, OpenGL is faster in others.
Those statements really doesn't tell the OP a whole lot (if anything) aside from the general notion that "it depends".
To be more descriptive, it really depends on which games you're playing, what hardware you're running, your drivers, and which revision of Dolphin you're using. Some people seem to get bad combos and OpenGL gives them no love no matter what they do, but others will find that it boosts speed significantly. There seem to be a lot of factors that go into the mix such that OpenGL is not always outright faster D3D11 (even when disregarding OpenGL's lower EFB2RAM performance) and vice versa.
Generally speaking though, a lot of people (at least those vocal enough to post about their experiences) report OpenGL being faster than D3D11 for them, while it appears a lower number of people report that to be the other way around. In terms of accuracy, the two are pretty much tied afaik; a minority of games have backend specific issues, like Sonic Heroes having graphical errors in OpenGL but not D3D11, or like Skyward Sword crashing in the Silent Realm when using D3D11 instead of OpenGL.
Ideally, I say you should just choose one, stick with it until you think it becomes a problem, then switch as needed. Using per-game .ini files to manage your settings, you don't even have to switch between backends in the GUI before playing.