Radeon Gallium3D R600g Color Tiling Performance

[phoronix]

Phoronix: Radeon Gallium3D R600g Color Tiling Performance

With 2D color tiling enabled by default in the R600 Gallium3D Radeon open-source driver as of this week, here are new benchmarks showing off the OpenGL performance impact of the 1D and 2D tiling methods for this common open-source AMD Linux graphics driver.

http://www.phoronix.com/vr.php?view=18099

[tmikov]

This confirms what I am seeing with my silly "one rotating static texture" test. No big improvement yet when I enable 2D tiling for textures and the frame buffer. Perhaps there is a specific usage scenario where 2d tiling helps and I am not hitting it, though I thought that rasterising a big texture is precisely that.

(BTW, I verified that it is indeed enabled by poking values directly. The sizzling pattern is insane! :-)

[glisse]

This confirms what I am seeing with my silly "one rotating static texture" test. No big improvement yet when I enable 2D tiling for textures and the frame buffer. Perhaps there is a specific usage scenario where 2d tiling helps and I am not hitting it, though I thought that rasterising a big texture is precisely that.

(BTW, I verified that it is indeed enabled by poking values directly. The sizzling pattern is insane! :-)

YOu won't exhaust GPU VRAM bandwidth with 1 big texture. You really need to push the bandwidth requirement to clearly see 2D tiling effect. 1 Big texture is not a test stressing the gpu.

[schmidtbag]

even if its just a few extra FPS here and there, it doesn't seem to have any regressions and every little bit counts. I kinda get the impression most of the ATI/AMD open source drivers are slow because of dozens of little things like this that are missing. I doubt that there are many core problems that would cause anything higher than say a 40% performance increase.

[Lemonzest]

Why a 4650 of all things?

[tmikov]

YOu won't exhaust GPU VRAM bandwidth with 1 big texture. You really need to push the bandwidth requirement to clearly see 2D tiling effect. 1 Big texture is not a test stressing the gpu.

Fair enough. But what would be a good synthetic stress test?

Also, do you have an idea why the blob is faster? Could it be memory clocks, power management, etc?

[energyman]

Why a 4650 of all things?

maybe because with such a low end card any improvements of 2d tiling will be lost and so he can write some more stupid articles?

4650 a 'midrange' card my ass. No, back then the 4770 was a midrange card. Nowadays a 5770/6770/7770 is a midrange card. 4650? That is low end in todays standards.

[pingufunkybeat]

Fair enough. But what would be a good synthetic stress test?

Also, do you have an idea why the blob is faster? Could it be memory clocks, power management, etc?

No, it's because it has millions of lines of code, specifically hand-optimized for every imaginable usage scenario under the sun, all tweaked with heuristics over 15 years of development.

The Mesa devs first try to implement all features in the natural, straight-forward way, and then optimise later, once the features are in place and stable.

[tmikov]

No, it's because it has millions of lines of code, specifically hand-optimized for every imaginable usage scenario under the sun, all tweaked with heuristics over 15 years of development.

The Mesa devs first try to implement all features in the natural, straight-forward way, and then optimise later, once the features are in place and stable.

Thank you for this generic armchair response, but that's not really what I am looking for. I am trying to find our why the blob is much faster at rendering a single texture.

All that talk about 15 years of optimization and special cases for games is utter nonsense, unless the fundamental underlying operations are fast. Things like 2D tiling is exactly the fundamental improvements I am talking about. Perhaps there is something else missing that we don't know about.

[pingufunkybeat]

Thank you for this generic armchair response, but that's not really what I am looking for. I am trying to find our why the blob is much faster at rendering a single texture.

In your case, it is about 4ms faster at rendering a single texture.

Optimising 4ms away is really hard work, especially if it consists of 100 different miliseconds collected across different parts of the driver. That's what my armchair response was about.