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.<p>That doesn't mean they're wrong about OpenGL being faster than DirectX, and even if they <i>are</i> wrong, it doesn't mean they're being intentionally misleading. But it's important to keep our eye on the priors.
I think the real interesting conclusion here is: if OpenGL has parity with Direct3D on Windows in terms of features and performance, why should anyone <i>ever</i> use Direct3D any more? Direct3D is almost non-existent on mobiles and tablets, so anyone using Direct3D is just making their lives harder if they want to go mobile, or port to any other OS. We don't live in Windows monopoly days any more. If OpenGL can get you the same thing on Windows, <i>and</i> helps make it easy to port to other big platforms, I can see Direct3D really falling to the sidelines.
Yes, DirectX benefits from network effects, but there are a ton of mobile game developers these days developing for Android and iOS in OpenGL ES, and I could see a day coming when these network effects are reversed in OpenGL's favor. The fact that Valve and EA are going to support Linux and OpenGL is just a bonus, although a pretty big one. And don't forget Blizzard's Diablo 3 and Starcraft 2 are also written in OpenGL for Mac OS X.
Why stop at OpenGL? Let's work with GPU vendors to get a more consistent, lower-level API for high-performance 3D graphics. John Carmack observed that not being able to program the hardware directly caused an order of magnitude drop in effective performance of PC hardware. <a href="http://www.rockpapershotgun.com/2011/06/08/get-with-the-programmer-carmack-speaks/" rel="nofollow">http://www.rockpapershotgun.com/2011/06/08/get-with-the-prog...</a>
My impression is that part of the issue is that OpenGL has only really gotten its act together, so to speak, recently and that fresh in the memory of many game devs was a time when DirectX really was obviously better.
This article completely missed the fact that there's way more to DirectX than just Direct3D. DirectInput, DirectPlay, DirectSound etc. are out-of-scope for OpenGL which means you have to add a <i>lot</i> of unrelated libraries to approach the same functionality as DirectX.
Sorry but Valve has been on a smear campaign to slow Windows 8 adoption for one reason, Microsoft will own the store and the keys. So I'm immediately skeptical of any information they put out there. A lot of their grumpy comments sound very similar to Sierra Games of the 80s and 90s that resisted the jump to Windows from DOS.<p>I do think this push into Linux is great for making Linux a richer platform overall. This way, everyone wins in that case, but I still do not see it an overly successful monetary venture.<p>If Windows 8 is a failure, people will either stay with what they know (Windows 7/XP) or continue to defect to OS X. Microsoft doing what they always do, will see where they need to improve, and continue to iterate and push out a more polished Windows 9.
<i>Is it time for an OpenGL revolution?</i><p>Perhaps not, lets wait until Valve has a chance to fix their D3D issues. It seems to me the blog post was more about success in ferreting out problems with drivers and APIs on Linux and Windows than pure Linux/OpenGL superiority.<p>I'm a longtime Linux user and there is little reason to assume Linux the is king of graphics. One thing worth pointing out is that Valve is using a Nvidia card with proprietary drivers which don't make use of any shared Linux graphics infrastructure (Gallium3D, etc). So this type of performance gain compared to Windows may not be repeatable with Intel or ATI cards.
What, only weeks after I threw away my (very) old OpenGL books? The reason why DirectX is used everywhere is that graphics cards have been developed to suit it better for the past 10 years or so, I thought. Also, DirectX is a more complete solution for developers including networking, audio, controller handling code ...
I'm slightly skeptical of their benchmarks -- the fact they're using 300fps numbers is a red flag. No one runs games at that speed. What's the comparison for a game running at 30 - 60fps? My hunch is that D3D has a tiny fixed per-frame cost that becomes irrelevant when frames take 10x longer to render.
"More developers use DirectX because it has a cleaner API and better documentation."<p>Sounds about right. If raw speed was more essential than less problematic development, we'd all be writing in assembler.
DirectX is a very good option for games. OpenGL on the other hand is a more generic 3D API (used, for example, by most CAD and other scientific applications). Additionally, of course, it is available on all platforms. I doubt that DirectX will outlive OpenGL in the long run.
Here is another, older take from Wolfire Games (Overgrowth, Lugaru):<p><a href="http://blog.wolfire.com/2010/01/Why-you-should-use-OpenGL-and-not-DirectX" rel="nofollow">http://blog.wolfire.com/2010/01/Why-you-should-use-OpenGL-an...</a><p>and a follow up:<p><a href="http://blog.wolfire.com/2010/01/DirectX-vs-OpenGL-revisited" rel="nofollow">http://blog.wolfire.com/2010/01/DirectX-vs-OpenGL-revisited</a>
This puzzles me. Last I heard, the Mac versions of Valve's games were slower than their Windows counterparts. So maybe it's more about the Linux kernel than about OpenGL? Is there any comparison between the three platforms on the same hardware?
<i>That 0.4 millisecond difference is down to how fast the DirectX pipeline can process and draw 3D data.</i><p>So let me see if I can follow this: OpenGL is faster than DirectX because...OpenGL is faster than DirectX?