4 ms·

While Valve is certainly in a position to know this, it's worth keeping in mind that they do have a horse in this race. For other legitimate reasons, Valve want

While Valve is certainly in a position to know this, it's worth keeping in mind that they do have a horse in this race. For other legitimate reasons, Valve wants to move away from Windows as a platform, and that requires that people be convinced of the viability of the alternatives, which in turn hinges on whether or not OpenGL is competitive with DirectX. That doesn't mean they're wrong about OpenGL being faster than DirectX, and even if they are wrong, it doesn't mean they're being intentionally misleading. But it's important to keep our eye on the priors.

kstenerud 14y ago
The problem is that ExtremeTech is slanting their words in order to sensationalize the story. Valve (in their blog post): "This experience lead to the question: why does an OpenGL version of our game run faster than Direct3D on Windows 7? It appears that it’s not related to multitasking overhead. We have been doing some fairly close analysis and it comes down to a few additional microseconds overhead per batch in Direct3D which does not affect OpenGL on Windows. Now that we know the hardware is capable of more performance, we will go back and figure out how to mitigate this effect under Direct3D." Extreme Tech: "As for why OpenGL is faster than DirectX/Direct3D, the simple answer is that OpenGL seems to have a smoother, more efficient pipeline. At 303.4 fps, OpenGL is rendering a frame every 3.29 milliseconds; at 270.6 fps, DirectX is rendering a frame in 3.69 milliseconds. That 0.4 millisecond difference is down to how fast the DirectX pipeline can process and draw 3D data."