[archagon]

Curious: how is performance compared to the OSX port? All the Source games I've tried run horribly on OSX compared to Windows on the same machine. Strangely, they play just fine through a Parallels Windows VM running inside OSX, so it can't be the OSX graphics driver's fault. What's going on over there?

[TazeTSchnitzel]

I believe OS X has graphics drivers provided by Apple, not by the hardware vendors, so that likely has something to do with it.

[archagon]

Yes — but as I said, running the game in a Parallels Windows VM results in 2x better performance than running the same game natively. The same OSX graphics driver is used in both cases, except the VM has to do extra work! How does that make any sense?

[olegoandreev]

A wild guess would be that OS X drivers contain poor shader optimizer.

Parallels probably work by decompiling DirectX shader bytecode back into GLSL, which is already optimized for OS X shader compiler, therefore there is less burden on the optimizer.

Another example of poor drivers are various GLES drivers on mobile, mostly trivial optimizations can drastically increase the performance: http://aras-p.info/blog/2010/09/29/glsl-optimizer/ and https://github.com/aras-p/glsl-optimizer

[archagon]

I was skeptical, but that first link speaks volumes. Interesting theory!

[TazeTSchnitzel]

>The same OSX graphics driver is used in both cases

Are you sure? I'd think it isn't passing function calls, but rather direct hardware access. I might be wrong.

[archagon]

Not 100% sure, but I was under the impression that unlike Windows (?), OSX simply does not allow you to have direct hardware access. (Plus, if Parallels was accessing the hardware directly, how would you be able to run the VM in a window while still doing OSX stuff underneath?)

Either way, there's clearly a way to make the game run significantly faster on OSX, but Valve isn't doing it for some reason.

[gizmo686]

I can't speak to OSX, but on linux I know that virtualbox likes to install kernel modules into the host. If your VM does that, then it should be able to get direct hardware access.

[TazeTSchnitzel]

VirtualBox on OS X uses an installer, instead of being a .app you can drag to your Applications folder, so I assume it does as much.

[lucian1900]

VM software will not ship with drivers for all potential GPUs.

They use the platform graphics APIs like any other app.

[rjzzleep]

i'm guessing you're talking about a discrete graphics card right?

i can't really give you an answer on this, but if i had to guess i'd say it works better on anything but radeon cards(but then again are radeon cards supported on macs nowadays?)

also, not exactly the same, but still interesting measurements.

http://www.phoronix.com/scan.php?page=article&item=ubuntu130...

valve worked closely with nvidia and intel to improve the performance and compliance of the drivers. check this out for example http://blogs.valvesoftware.com/linux/faster-zombies/

[davb]

I don't have a Mac so can't compare, but on my machine (xUbuntu 13.10, Intel Core i70470K (not overclocked), Asus NVidia GTX 770 2GB GDDR5, 32GB Corsair Vengeance CL10, Corsair M500 SSD 960GB) it runs buttery smooth at full settings.

I'm using the NVidia latest stable drivers (from the NVidia website), which were a pain to install under *buntu.

It actually seems a lot smoother running natively compared to running under Wine. I can't put my finger on it. The frame rate under Wine seems OK. The image looked fine. But it didn't "feel" right.

[M4v3R]

It wasn't the case for me. Portal 2 worked fine on my Air with Intel HD 4000 graphics. Well, I didn't beef it up to maximum detail level, but it ran pretty smoothly.