Developers Are Still Working On OpenGL 4.x For Intel Haswell / Ivy Bridge

[phoronix]

Phoronix: Developers Are Still Working On OpenGL 4.x For Intel Haswell / Ivy Bridge

The developers at Igalia continue working on the necessary OpenGL functionality to be able to advertise OpenGL 4.x support in Mesa for Ivy Bridge and Haswell "Gen 7" graphics...

http://www.phoronix.com/scan.php?page=news_item&px=Intel-OGL4-Gen-7-Progressing

[Barnabas]

Does anyone know if they plan on supporting the older Sandy Bridge units? I have some older NUCs I use for HTPCs...not sure if OpenGL 4.x support would benefit them though.

[Kano]

Very interesting blog entry, will be interesting to test some OpenGL 4 games with older Intel chips. I don't expect performance records however...

[cl333r]

I'm using Haswell and I'm far more interested in Vulkan support than GL 4 (actually I'm not interested in GL4 at all since I'm not a gamer).
Although it was reported that with Mesa 12 Ivy Bridge chips and later support Vulkan, in reality the top 3 simplest Vulkan testing example source code I found on Google failed to run (but did compile), not to mention Fedora 24's recent update from Mesa 11.2 to 12 didn't include Vulkan support at all and I had to use a vulkan copr from the web.

[Gusar]

Does anyone know if they plan on supporting the older Sandy Bridge units? I have some older NUCs I use for HTPCs...not sure if OpenGL 4.x support would benefit them though.

OpenGL 4.x is impossible on Sandy Bridge because it can't do tessellation. Now, whether it is capable of fp64, that I don't know, but considering how much hassle it is to implement it for Haswell and Ivy, I doubt anyone would bother with Sandy Bridge even if it was possible.

cl333r: Fedora's mesa update missing Vulkan is just an oversight, it'll happen. Support for Ivy is still incomplete anyway, so failures like what you're seeing are not unexpected.

[Mystro256]

OpenGL 4.x is impossible on Sandy Bridge because it can't do tessellation. Now, whether it is capable of fp64, that I don't know, but considering how much hassle it is to implement it for Haswell and Ivy, I doubt anyone would bother with Sandy Bridge even if it was possible.

I'm pretty sure this is because there is no hardware support for it, so it needs to "emulate" it in a way. The blog post actually explains it a bit:

Implementing fp64 requires a lot of changes throughout the driver compiler backends, which makes the task anything but trivial, but the vector backend is particularly difficult to implement because the hardware only supports 32-bit swizzles ... As a consequence, dealing with anything bigger than a dvec2 requires more creative solutions...

Sandy bridge probably could support fp64 via the same means, but it seems unlikely they would put the hassle into development and testing.

[haagch]

Ivy Bridge actually runs quite many of the examples you can find. For example most of https://github.com/SaschaWillems/Vulkan work and the Hologram example from the LunarG Vulkan SDK works now too. From other users here on Phoronix I heard that Haswell may actually have more problems than Ivy Bridge. But they are both incomplete, so that doesn't mean much.

[axfelix]

Honestly, fp64 is so impractical on all but the highest-end Intel GPUs I'm surprised they're bothering (that hardware limitation that requires them to emulate part of the feature set should be telling) -- if only it weren't part of the required OpenGL spec to be able to declare 4.x+.

The stencil texturing is the other thing that's only on Broadwell+ right now, and that one I'm not too sure about.

[Gusar]

The stencil texturing is the other thing that's only on Broadwell+ right now, and that one I'm not too sure about.

Code for that is already written: gen7-stencil_texturing. Some fixing is still being done, but gen7 will have stencil texturing soon™

[Kano]

haagch

Some run but render something else if you compare it against Nvidia. But for games you can forget it, Haswell and Dota 2 no way. Talos no way - completely useless these days. Maybe Intel can run the minimal Vulkan compliance suite but no real games.

OpenGL is basically much better, with some overrides games like DiRT Showdown and Bioshock Infinite worked (720p lowest). I don't know how many games use fp64 but you don't need any overrides anymore which is much simpler for normal users.

But nobody should expect high speed gaming, that was never the purpose of those iGPUs. I doubt that anybody will play demanding OpenGL 4 games with it, they should render correctly but can be very slow.