Valve: OpenGL is faster than DirectX — even on Windows

http://www.extremetech.com/gaming/133824-valve-opengl-is-faster-than-directx-even-on-windows

by mrsebastian • 14 years ago

127 69 14 years ago

mtgx2• 14 years ago

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.

masklinn4• 14 years ago

> 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.

I'm pretty sure we're seeing that already. And WebGL is not going to improve the situation for D3D.

lazyjones• 14 years ago

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 ...

seanmcdirmid2• 14 years ago

OpenGL ES 2.0 is actually pretty clean; the monstrosity that is other OpenGL is basically being held up by the CAD companies (such as AutoDesk) who are very conservative and don't care much about games; they just want their old code to keep running on new versions of the spec.

ajax77• 14 years ago

This simply isn't true. A number of years ago with the introduction of DirectX 10, Autodesk began transitioning several mainstay products to exclusive DirectX use under Windows (see http://archicad-talk.graphisoft.com/files/autodesk_inventor_...) Morevoer, Autodesk has moved to using a modern, unified renderer for a large number of their products. There may be other CAD companies "holding up" the "monstrosity" of dated OpenGL versions, but Autodesk is not that company. In all likelihood, the issues lies not with the CAD companies, but with their clients that refuse to upgrade their legacy applications of 10-15+ years age.

msbarnett• 14 years ago

> Also, DirectX is a more complete solution for developers including networking, audio, controller handling code

I gather you're talking about DirectPlay, DirectSound, and DirectInput?

They've all been deprecated and removed from modern versions of DirectX. You need to pull in other libraries to replace those portions (Games for Windows Live, XAudio2, and Windows Message Loop + XInput is one way to roll up that functionality).

Honestly DirectX is mostly just Direct3D in modern incarnations. The situation is fairly similar to modern OpenGL.

kmm2• 14 years ago

Your old OpenGL books would have been worthless, as they can only have talked about the fixed pipeline which has been deprecated (thank god).

Symmetry• 14 years ago

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.

naner• 14 years ago

Is it time for an OpenGL revolution?

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.

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.

bryanlarsen3• 14 years ago

Valve has been optimizing Source on Direct3D/Windows for 10 years, so I don't think waiting any longer will help.

sp3323• 14 years ago

Valve's own blog seems to think it will: "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." http://blogs.valvesoftware.com/linux/faster-zombies/

stewie22• 14 years ago

cards are very different, even the driver is open sourced, I don't think other cards can benefit from it.

andybak• 14 years ago

The post title bears little relation to the linked article's title.

ben0x539• 14 years ago

From the article body:

> we could be on the cusp of an OpenGL revolution

Close enough?

bryanlarsen3• 14 years ago

True, but it better represents the linked article's body IMO.

bryanlarsen3• 14 years ago

And of course the mods have gone and messed things up again.

sp3323• 14 years ago

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 lot of unrelated libraries to approach the same functionality as DirectX.

jiunec• 14 years ago

That's not really so much of a problem as you might think:

http://www.libsdl.org/

parbo2• 14 years ago

The lead developer of SDL is now working at Valve, so I guess that is a very likely solution.

masklinn4• 14 years ago

On the other hand,

> DirectInput

Officially deprecated for Windows Message Loop and XInput

> DirectPlay

Deprecated for GFWL, not even present anymore in the DirectX SDK (I believe), some modules (voice and NAT helpers) were completely removed in Vista.

> DirectSound

Deprecated for XAudio2 (Vista and 7 implement DirectSound in software, although ALchemy will dynamically intercept DirectSound3D calls and translate them to OpenAL on the fly on Audigy and X-Fi)

sp3323• 14 years ago

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. http://www.rockpapershotgun.com/2011/06/08/get-with-the-prog...

mtgx2• 14 years ago

How would that work? Would it need to use C? Would this help?

http://hsafoundation.com

kabdib• 14 years ago

Because isolation from dozens of graphics architectures (many from the same vendor) and hiding chipset bugs (not just in the graphics hardware, btw) that would scare the jebus out of you is worth it. Not having to track down wierd synchronization issues is like money in the bank to most developers.

Make every game reinvent their own chip-level drivers? Wow. You want to run 10X faster, or slip your schedule by years?

bcrescimanno2• 14 years ago

Well said. Let's be honest, John Carmack is something of a rarity even in the gaming world. While I'm certain that he could handle the challenges associated with tearing down those abstractions, I'm not sure the throngs of other developers would fare so well.

Listening to people like Carmack, Torvalds, and others of their ilk is a good thing; but, we need to be cognizant that they are, themselves, special cases in the world of engineering and what can work well for them likely won't work well for the other 90% of the engineering world.

ralfn2• 14 years ago

You can get the best of both worlds, with opensource drivers though.

They imply well documented hardware and the potential to access it directly. But you can also use, and/or help improve the the higher levels of abstraction.

tathagata• 14 years ago

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.

kmm2• 14 years ago

> DirectX is a very good option for games. OpenGL on the other hand is a more generic 3D API

I don't know about that any more. I have heard that for about a decade, but with the massive changes that have been made to OpenGL, I don't see why that should still be true, if it even was true in the first place.

AshleysBrain• 14 years ago

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 ever 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, and helps make it easy to port to other big platforms, I can see Direct3D really falling to the sidelines.

TylerE2• 14 years ago

Because it ISN'T feature parity.

In OpenGL all the fun stuff (e.g. the stuff that's in DX9+) is in vendor specific extensions.

A bit like vendor prefixes in CSS, except they can actually be implemented differently, have different names, etc. It's BAD news, and the main reason why 99% of AAA games use DirectX on Windows.

ginko2• 14 years ago

That might have been true in the OpenGL 1.5 days.

There are few things one might miss in core OpenGL 4.2. If anything any features exposed in extensions building on OGL 4.2 are so new or experimental that D3D doesn't have them at all.

bcrescimanno2• 14 years ago

One word: inertia.

The question development shops would be asking themselves is: will the additional revenues provided by Linux / Mac ports of these games be enough to offset the cost of retraining their people (or hiring new people) who are prepared to do serious OpenGL development?

Moreover, many game companies are using licensed game engines. These engines may not now (or ever) support OpenGL, so the game developers themselves may not have the option to change--even if they did want to.

malkia• 14 years ago

I've met a lot of graphics programmers, that are simply in love with D3D, and despise OpenGL (my own experience, I work in a video game studio doing console and PC games)

angersock3• 14 years ago

That's all well and good, but the fact remains that Direct3D is certainly a better documented API, and also that OpenGL even now has annoying remnants of its past as a hissing, clanking state-machine (glBind* garbage). Speaking from experience, trying to get OpenGL to behave sanely in a multithreaded environment is nontrivial.

testdfsg2• 14 years ago

You are right. OpenGL works everywhere.

But you have to be careful: my amateur OpenGL 3d game had problems running on half of computers, especially laptops. It's because various cards support different opengl extensions. You can't use non-power-of-two textures, can't use textures bigger than 512x512 (or other number), can't generate mipmaps automatically, can't have too big display lists.

I thought about optional DirectX renderer when running on Windows, because I've heard it's more standarized.

Flow• 14 years ago

But now you know about those limitations :-)

warmwaffles• 14 years ago

The non power of two issue is not a problem. Just load the texture in with padding to get it to the next power and put a texture region in that doesn't have the padding.

OpenGL is an awesome platform for those who want system portability IE minecraft, or any other indie developer who wants maximum exposure.

n00b101• 14 years ago

Yes, yes it is. Now can OpenGL please get their act together and create a respectable SDK and documentation?

neop• 14 years ago

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?

overshard• 14 years ago

The problem with Mac OS, that it's always had with every 3rd party built-in library, is that the OpenGL they use is extremely outdated.

Source: Current version on newest OS X if you don't want to support Legacy OS X is 3.2, Legacy OS X is 2.1 https://developer.apple.com/graphicsimaging/opengl/capabilit...

Most recent OpenGL is 4.2. http://www.opengl.org/

Most OS X coders, till the recent OS X release have been using 2.1 which was released in 2006 which is when OpenGL was inferior to DirectX in every way.

masklinn4• 14 years ago

> This puzzles me. Last I heard, the Mac versions of Valve's games were slower than their Windows counterparts.

That's in part a driver issue (though Mach message traffic may also limit perfs), the drivers are mostly developed in-house by Apple, and Apple is notoriously hard to work with (for third parties). So while Valve did lead to significant performance improvements following Steam/OSX I would expect they couldn't work closely with internal drivers developers.

And game perfs probably still isn't the main focus for OSX drivers development, sadly.

CountSessine• 14 years ago

the drivers are mostly developed in-house by Apple

Really? Are you sure about that? I'm pretty sure that while there's some Apple-supplied kernel-mode glue, and maybe a lot of user-space components, most of the driver code is actually supplied by NVidia/AMD/Intel.

In fact at one time or another OSX seems to have inherited funny GPU driver bugs that were common with Windows (like the way NVidia's 32-bit drivers were unhappy with living outside the 2GB-4GB memory range).

led762• 14 years ago

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.

stewie22• 14 years ago

when you turn on vsync, the frame rate is at most 60. When you turn it off, you certainly can have 300fps.

led762• 14 years ago

Sorry, my point was that they picked a benchmark that was too easy. I suspect if the machine was straining to hit 60fps their results could be vastly different. That's how most games run, so that'd be more interesting to see.

Retric• 14 years ago

That would change the size of the effect, but OpenGL would still be faster. Also, 60fps x 5 = 300, so 1/5th of 20% ~= 4% faster which is still significant for them.

mistercow• 14 years ago

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• 14 years 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."

SoftwareMaven• 14 years ago

That 0.4 millisecond difference is down to how fast the DirectX pipeline can process and draw 3D data.

So let me see if I can follow this: OpenGL is faster than DirectX because...OpenGL is faster than DirectX?

danudey• 14 years ago

OpenGL is faster than DirectX because the pipeline is shorter/faster/more efficient/etc. i.e. it's not due to texture copying, worse memory addressing, driver issues, programmer error, etc.

farinasa• 14 years ago

Here is another, older take from Wolfire Games (Overgrowth, Lugaru):

http://blog.wolfire.com/2010/01/Why-you-should-use-OpenGL-an...

and a follow up:

http://blog.wolfire.com/2010/01/DirectX-vs-OpenGL-revisited

jarjoura• 14 years ago

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.

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.

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.

duaneb• 14 years ago

OpenGL is still available through Windows. It's hard to see this as a "smear campaign" on anything but the Direct3D batch processing.

goostavos• 14 years ago

Did you read the actual Valve blog post, or just the sensationalist ExtremeTech article? If you read the former, you'll have to point me to the part where they did the smearing. I must have missed it.

uvTwitch• 14 years ago

"More developers use DirectX because it has a cleaner API and better documentation."

Sounds about right. If raw speed was more essential than less problematic development, we'd all be writing in assembler.

krob• 14 years ago

I coulda told everybody that.

Valve: OpenGL is faster than DirectX — even on Windows

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