Trying R600g On Mesa 11.3, Cayman GPU On Linux 4.7 Radeon DRM Yields Problems

[phoronix]

Phoronix: Trying R600g On Mesa 11.3, Cayman GPU On Linux 4.7 Radeon DRM Yields Problems

For those curious whether Mesa 11.3 improves the performance at all for users bound to an old AMD Radeon graphics card using the R600 Gallium3D driver, I have some tests of that to share this morning...

http://www.phoronix.com/scan.php?page=news_item&px=R600g-Mesa-11.3-FirePro

[boffo]

There is a bug with the APUs with r600, that can slow down the system with kernel>4.4, but it can be solved by following https://bbs.archlinux.org/viewtopic.php?id=211365

I'm not sure if it affects also discrete cards.

[Mez']

I happen to have a Northern Islands (6480G SUMO/6650M TURKS) hybrid laptop which in theory should support OpenGL up to 4.3 but in practice with open drivers is stuck at 3.3, I guess for the reason you mentioned. Fortunately, we can override this (for games such as Dirt Showdown).

Since I upgraded Ubuntu from 15.10 to 16.04, after 8 years or so of fglrx on 2 laptops I was forced to switch to open drivers, Hence, for the last 2 months I've been testing many mesa and kernel versions: 11.0, 11.2, 11.3-devel (either oibaf or padoka); kernels 4.2, 4.4, 4.5, 4.6 (all RCs + final) and Michael's optimized 4.7 image for AMDGPU.

I didn't quite notice much of a difference all in all between these versions. I never got the chance to compare the performance with Windows (first boot was with a LIVE CD in to format the disk and install Ubuntu). But it still performs below fglrx in a noticeable way.

Michael, regarding 4.7 drm-next are we talking about the one optimized for amdgpu or a different one? Is there a real enhancement specific to r600g when compared to stock 4.6 final?


P.S: Thanks not to forget r600g Michael. Some of these Northern Islands GPU are only 4 years old after all, and you can keep a good quality laptop easily for 5 to 8 years. My ASUS is still in perfect state, and I have no intention to scrap it to succumb to commercial marketing wanting you to generate waste for the sake of business.

[eydee]

Taking a look at the r600 bugtracker shows more serious regressions than some performance loss. It's a shame these cards are legacy now, they still support all the mainstream features that are used in graphics today. And the mainstream won't change at least until 2020, because game developers can't drop support for Windows 7.

[schmidtbag]

And the mainstream won't change at least until 2020, because game developers can't drop support for Windows 7.

Not sure I entirely agree:
* To my knowledge, Vulkan is Windows 7 compatible
* Many devs seem to be favoring Vulkan over DX12, or at the very least, supporting both
* Windows 7 won't be supported anywhere near as long as XP has.
* Most people who matter have actually upgraded from W7 to W10. Everyone else is either using office PCs, has no intention on playing games, or are stubborn fear-mongers who refuse to upgrade for petty or irrelevant reasons.
So, though I'm not sure if Vulkan or DX12 will be mainstream, I do think they'll be commonly available by 2018. Back in the DX10 days, many games shipped with both DX10 and DX9 binaries.

[Veerappan]

I have a HD6870 so this is really bad : "other Radeon HD 6000 series (Northern Islands) hardware is left out due to R600g not having floating point emulation support"

bridgman is this feature coming in the future by AMD or is this generation left in the dark for all times?

I don't think it got approved (but I'm not sure).... but there was at least a GSoC/EVoC proposal and interested student to implement emulated fp64 in mesa for mesa drivers that didn't have hardware fp64 support.

It was listed here under "Soft" double precision floating point support: https://www.x.org/wiki/SummerOfCodeIdeas/

[agd5f]

I don't think it got approved (but I'm not sure).... but there was at least a GSoC/EVoC proposal and interested student to implement emulated fp64 in mesa for mesa drivers that didn't have hardware fp64 support.

It was listed here under "Soft" double precision floating point support: https://www.x.org/wiki/SummerOfCodeIdeas/

Yes, that is one of the xorg gsoc projects.

[89c51]

Yes, that is one of the xorg gsoc projects.

Gsoc projects usually get abandoned so i am not expecting much on this. Would be better if someone else (probably a payed dev) solved it.

[smitty3268]

Gsoc projects usually get abandoned so i am not expecting much on this. Would be better if someone else (probably a payed dev) solved it.

I'd rather have the paid devs focus on getting Polaris support up and Vulkan running, than working on 6 year old cards.

It would only take a single line of code to "fake" the fp64 support on older cards anyway, and that's good enough for all current games. So if it's important to you, just write the 1-line-of-code patch and be done with worrying about it.

[Mez']

I'd rather have the paid devs focus on getting Polaris support up and Vulkan running, than working on 6 year old cards.

It would only take a single line of code to "fake" the fp64 support on older cards anyway, and that's good enough for all current games. So if it's important to you, just write the 1-line-of-code patch and be done with worrying about it.

It's less than 5 years old hardware, that for the most part does have OpenGL 4.3 compliancy. It is omnipresent in 4 years old laptops of that period. Not everyone buys a new laptop every two years regardless of the generated waste. Plus, these cards still have enough in the bag to play games with an acceptable comfort. And above everything, people invested their money in these laptops, and they have the right to get some return out of it.
Hence, whether you want it or not, this has to be worked on, independently of the support for newer hardware.