Valve's L4D2 Is Faster On Linux Than Windows

[Khudsa]

Why not? This is a DX9-game. Apple's OpenGL may not entirely be up-to-date, but it is well above DX9-level (again, we are talking 10-year old technology here). That is not the issue.
I see no reason why it would be any different on linux.
I also find Valve's figures highly suspect in light of my own OpenGL code, as well as other benchmarks that are cross-platform and/or cross-API, such as Unigine Heaven.

Valve is targeting right now the binary blobs, these blobs have a common base between windows and linux. I said that 'a priori' it will not have, but obviously I don't know, only with a direct comparison when the game is released we will know.

[Scali]

Valve is targeting right now the binary blobs, these blobs have a common base between windows and linux.

And OS X (and FreeBSD, and Solaris)
http://developer.download.nvidia.com...r-overview.pdf

The code base for the NVIDIA graphics driver leverages the majority of the source code
across all the operating systems we support. Everything that is specific to a particular
operating or windowing system is abstracted behind interface layers. In other words, the core
OpenGL driver source code is used on Microsoft Windows, Linux, Solaris, FreeBSD, and
Mac OS X. Similarly, most of the code for the NVIDIA kernel module is common across all
of those operating systems.

[Khudsa]

And OS X (and FreeBSD, and Solaris)
http://developer.download.nvidia.com...r-overview.pdf

That's something I don't know, that osx have the same codebase.

[Scali]

That's something I don't know, that osx have the same codebase.

Common sense, isn't it?
Why would nVidia maintain a separate codebase for OS X, when most of it is the same as for the other OSes? (And if anyone thinks that Apple or Microsoft write their own drivers: n00bs)

So back to my question: why would linux be any different from OS X, given that they both use the same OpenGL codebase?

[Khudsa]

Common sense, isn't it?
Why would nVidia maintain a separate codebase for OS X, when most of it is the same as for the other OSes? (And if anyone thinks that Apple or Microsoft write their own drivers: n00bs)

So back to my question: why would linux be any different from OS X, given that they both use the same OpenGL codebase?

Well, I know that windows and linux have the same codebase but I never heard anything about osx, and going on it's own opengl version and not following that the driver support don't help in that matter. It's common sense that the driver is made by nvidia and maybe apple puts some layer or something like that.

[Scali]

Well, I know that windows and linux have the same codebase but I never heard anything about osx

Well, it's right there in nVidia's own docs. In the exact same sentence that also explains that Windows and linux share the same codebase... So how could you (or anyone else) possibly have missed that? Selective reading much?

and going on it's own opengl version and not following that the driver support don't help in that matter. It's common sense that the driver is made by nvidia and maybe apple puts some layer or something like that.

The difference is mainly that afaik only Apple distributes the drivers, instead of just downloading the latest ones directly from nVidia.
Aside from that, Apple has some custom extensions (then again, so do X and Windows in the form of GLX and WGL), and Apple wants to keep the OpenGL version the same across all vendors, to avoid compatibility issues. So their OpenGL versioning is lowest-common-denominator pretty much. Even though nVidia and AMD have OpenGL 4.2 support in their codebase, they only expose version 3.2 on OS X (but they do expose their extensions).
But again, that's still plenty for a 10-year old DX9 game.

[kwahoo]

Common sense, isn't it?
So back to my question: why would linux be any different from OS X, given that they both use the same OpenGL codebase?

Because OGL implementation is shared between all manufacturers. Check fig. 1-5 https://developer.apple.com/library/...1987-CH208-SW1

The common OpenGL framework layer is the software interface to the graphics hardware. This layer contains Apple's implementation of the OpenGL specification.

[Scali]

Because OGL implementation is shared between all manufacturers. Check fig. 1-5 https://developer.apple.com/library/...1987-CH208-SW1

I guess you missed the part where they explain the driver layer:

The driver layer contains the optional GLD plug-in interface and one or more GLD plug-in drivers, which may have different software and hardware support capabilities. The GLD plug-in interface supports third-party plug-in drivers, allowing third-party hardware vendors to provide drivers optimized to take best advantage of their graphics hardware.

That's where the actual hardware-accelerated vendor driver plugs in. Which is what you'd normally be using under OS X. Apple does provide a software implementation as a fallback, but it is not suitable for playing games like L4D.
They even drew you a picture:

[89c51]

It would still be so much nicer if someone would just publish a replacement API for OpenGL that worked more like any other API designed in the last 15 years. And did so without tethering it to the clusterfuck that is Khronos. And spent time integrating Mesa's software renderer into a steppable shader debugger. Linux with Gallium is the perfect place for this since you can write a new API and get direct hardware acceleration without needing to wait for any hardware vendors to get on board. Just sayin'. Nudge nudge.

Is there anyone with interest in replacing OpenGL(Linux or not)?? In case there is such a big demand for D3D on Linux they can write a State tracker and be done with it. Can't they??

[Scali]

Is there anyone with interest in replacing OpenGL(Linux or not)?? In case there is such a big demand for D3D on Linux they can write a State tracker and be done with it. Can't they??

I believe they already did a D3D tracker as a proof-of-concept, using Gallium to build a Windows driver.
That should easily be portable to linux.
But the biggest problem is that most linux drivers don't make use of Gallium. Certainly not the only two drivers that really matter: AMD's and nVidia's binary drivers.