R600 Gallium3D Gains FP64 Support, Knocks Down Some GL 4.0/4.1 Extensions

[phoronix]

Phoronix: R600 Gallium3D Gains FP64 Support, Knocks Down Some GL 4.0/4.1 Extensions

For those riding Mesa Git master rather than the newly-released Mesa 11.0, there's now FP64 support in the R600 Gallium3D driver for select GPUs...

http://www.phoronix.com/scan.php?page=news_item&px=R600g-Lands-FP64-Native

[Redi44]

Does anybody know if the OpenCL image support for R600 will be integrated into the mainline? And if so, does anybody know when?

[MoonMoon]

I don't get that, can someone please clarify for me? If hardware like the HD6870 (BARTS) doesn't support fp64 fully, how does the Catalyst driver achieve compliance with these newer OpenGL levels, if that support is needed for these levels?

[Ericg]

I don't get that, can someone please clarify for me? If hardware like the HD6870 (BARTS) doesn't support fp64 fully, how does the Catalyst driver achieve compliance with these newer OpenGL levels, if that support is needed for these levels?

OpenGL compliance can either be done in hardware (fast) or in software (slow). Catalyst probably does it in their driver and then just eats the performance hit.

[boffo]

I don't get that, can someone please clarify for me? If hardware like the HD6870 (BARTS) doesn't support fp64 fully, how does the Catalyst driver achieve compliance with these newer OpenGL levels, if that support is needed for these levels?

Not all of the 5000 and 6000 series support all OpenGL 4. If the hardware doesn't support a feature they will use the software support or a mix of hardware and software support. The downside is that those feature will be slow.
This is nothing new. I still have an NVIDIA fx 5000 that I don't use anymore. It supports OpenGL 1 in hardware and OpenGL 2 in software. I could never use OpenGL 2 on linux. The same is true with the current hardware both AMD and NVIDIA support say they have full DirectX 12 support. In reality only a subset of feature in supported in hardware by bought companies. For more info check the Wikipedia page and then select your architecture.

[plonoma]

OpenGL compliance can either be done in hardware (fast) or in software (slow). Catalyst probably does it in their driver and then just eats the performance hit.

And I prefer they leave out the support from partially supporting hardware. It's better that way.
You don't want unsupported features pretending they are supported leading to ruining your performance.
And not a little bit either, making games unplayable.

Do keep in mind these graphics API's are meant to make hardware functionality accessible.
Their purpose is to access hardware, not to emulate hardware in software.

[dungeon]

I don't get that, can someone please clarify for me? If hardware like the HD6870 (BARTS) doesn't support fp64 fully, how does the Catalyst driver achieve compliance with these newer OpenGL levels, if that support is needed for these levels?

They emulate missing features, same thing nvidia and intel do.

I know what you think that ideally no drivers should not do ever do that and i think the same, but it just happens sometimes one feature does not hurt much. As example we can say that well even Vulkan can be implemented for VLIW5 - that is true but that is a case where amount of emulation needed probably exceed level which can make any sense

[Nille_kungen]

I don't get that, can someone please clarify for me? If hardware like the HD6870 (BARTS) doesn't support fp64 fully, how does the Catalyst driver achieve compliance with these newer OpenGL levels, if that support is needed for these levels?

I don't know about barts but it seems to support opengl 4.3 and i think it's evergreen so i guess it will be supported.
On the mesa developer mailing list they talked about older that supported partial fp64 like rv670/770 that's HD3850 and HD4000 IIRC.

http://lists.freedesktop.org/archives/mesa-dev/2015-September/094134.html

[mcirsta]

It seems Evergreen or better are getting OpenGL 4.0 so I guess I'm lucky as I have a HD5670 which looks like it will be supported. Older hardware probably lacks too much of the needed support to have OpenGL 4.0 but still we're lucky AMD still maintains proper open source support for these, it's much better than what nVidia does and only Intel is better at it.

[89c51]

Is this feature going to be emulated in SW for the cards that don't support it in HW?