A Four Way Comparison For Alien: Isolation Shows Off The Performance Difference

We all know third-party ports of DirectX games to OpenGL are going to have decreased performance. This has been true in every port I've seen. It might be different when it comes to porting DirectX 12 to Vulkan, but the ultimate goal, I would think, would be to have games developed with Linux in mind from the beginning. Games like that always perform very well.

Quoting: nattydread

Quoting: TheBoss

Quoting: nattydreadis it a native build or a port?

It was ported by Feral Interactive, and it is native. A port doesn't make something not native.

well what I mean perhaps is: does it use a wrapper to DirectX or does it directly use OpenGL? There must be some reason it doesn't perform as well on SteamOS.

Directx wrappers are obviously always less performant under linux, and opengl is also slower under linux than windows.


Last edited by sigz on 18 November 2015 at 12:35 pm UTC

Why is openGL slower under linux than windows?
I'm surprised by that!

Thanks for all the answers!

Quoting: sigz

Quoting: nattydread

Quoting: TheBoss

Quoting: nattydreadis it a native build or a port?

It was ported by Feral Interactive, and it is native. A port doesn't make something not native.

well what I mean perhaps is: does it use a wrapper to DirectX or does it directly use OpenGL? There must be some reason it doesn't perform as well on SteamOS.

Directx wrappers are obviously always less performant under linux, and opengl is also slower under linux than windows.

Not always:
View video on youtube.com

View video on youtube.com

30-40% performance difference nvidia vs nvidia with different OS it's a fail, the game is perfectly playable but to sell something you nedd to build some motivation to switch.
Right now it's a question just to have it rather than how it perform... and this is a shame.

Quoting: nattydreadWhy is openGL slower under linux than windows?
I'm surprised by that!

Thanks for all the answers!

It's not, but the game-specific optimisations that are in the Windows driver are not enabled in the Linux driver.
Apart from that, depending on how the game is written, the performance will differ between Linux and Windows, sometimes better on Linux, sometimes better on Windows. Here are some recent test results as an example.


Last edited by Cybolic on 18 November 2015 at 1:16 pm UTC

If u got the time to manage these kind of videos in the future, I would love it ^^.
Its always intressting to compair different builds and os's.

Dunno if this is a GoL channel. Anyways I enjoyed this.
And lets hope we get vulkan soon ^^

Hmmm, interesting comparison but isn't this more a comparison between OpenGl vs. D3D than StemOS(Linux) vs. Windows ?
I mean, under what API is the Windows Version running ? Has the Windows-Version an OpenGl renderer or ist it only D3D ?

Nether the less for me Feral-Interactive did a very good Job with this Port of Alien Isolation ! For me, everything running constantly over 60 Fps is a very good Result.

Quoting: Cybolic

Quoting: nattydreadWhy is openGL slower under linux than windows?
I'm surprised by that!

Thanks for all the answers!

It's not, but the game-specific optimisations that are in the Windows driver are not enabled in the Linux driver.
Apart from that, depending on how the game is written, the performance will differ between Linux and Windows, sometimes better on Linux, sometimes better on Windows. Here are some recent test results as an example.

At best you will have near same fps as in windows in some cases, most of times you will get lower fps, and you will never have a 30% more fps on linux than windows.


Last edited by sigz on 18 November 2015 at 1:50 pm UTC

Quoting: GuestI can't comment on SteamOS internals, but it's a source code based interface of DX, as far as I know. I don't mean they implement DX using OpenGL, but that they provide the same interfaces at a source code level, as far as the game code is concerned. It's all compiled natively in the end.

You mean Feral's using something like togl for their ports? Have they confirmed this or is this based on your own research? As Valve showed back in the day, this can work well for most dx9 level stuff at least, but some stuff in the APIs will require a lot of intermediate processing to make the interfaces "compatible". Especially if the original code gets creative with threads. This approach is valid though if they need to keep their changes separate from the original codebase for... reasons.