AMD Polaris Doesn't Support ETC2 Texture Compression

[ResponseWriter]

Hi,

ETC2 is supported by all Mesa/Gallium drivers (R300-R500, R600-R700, Evergreen, Cayman, SI, CI, VI, Polaris).

Only AMD Stoney can do ETC2 in hardware, but for other chips the drivers convert ETC2 into other supported formats.

Out of curiosity, is this format conversion using some sort of cache and if not, is that something to be implemented? Also interested in progress of the on-disk shader cache. Load times are still slow for me compared to what friends on Windows get so anything that helps...

[Serafean]

Hi,

ETC2 is supported by all Mesa/Gallium drivers (R300-R500, R600-R700, Evergreen, Cayman, SI, CI, VI, Polaris).

Only AMD Stoney can do ETC2 in hardware, but for other chips the drivers convert ETC2 into other supported formats.

The bottom line is ETC2 is supported by the drivers and applications can use it freely. (the article should be corrected, or otherwise it may really suppress adoption of ETC2)

ping Michael ?

[marek]

Why is it only supported in hw in stoney and not polaris?
Is there no win to do it in hw opposed to software or does it make you compromise on other functions?

I don't know why. Maybe ETC2 is not very important on desktop given that DirectX doesn't support it. I have yet to see an app using ETC2 on Linux.

Apps can use BPTC and RGTC instead of S3TC, so there is even no "legal" need to have ETC2 on desktop.

You can still use ETC2 if you want. Our drivers support it.

[marek]

Out of curiosity, is this format conversion using some sort of cache and if not, is that something to be implemented? Also interested in progress of the on-disk shader cache. Load times are still slow for me compared to what friends on Windows get so anything that helps...

The format conversion is trivial and happens during texture loading. There is no impact while rendering (other than the fact the texture format is different).

Regarding the on-disk shader cache, it really depends on whether it would improve your load times. Have you used a CPU profiler to see where the CPU is spending time?

[liam]

Yeah try conveying that to every single game developer that currently has games relying on ETC2... Lack of support is lack of support, it doesn't matter if ASTC is better, that's no reason not to support ETC2.

I mean... Might as well say: "Hey, Nvidia cards are a little better than AMD cards today in general. Let's only support Nvidia cards then!" (see what I mean?)

You can tell everyone how much superior PNG is to JPG, not everyone will use it, many people won't even care or won't even understand why they should prefer one over the other.



If people cared about what's best, PNG would be in the most widespread use today. Why isn't it? Because people used JPEG. Why? Just because... (It was the default format of some programs and camera devices)...

Hell, it makes me fucking sick that most digital cameras default to JPEG format and this cannot be configured to PNG output instead. PNG is basically better for everything and should always be used unless filesize is critical (JPEG has stronger compression than PNG resulting in slightly smaller filesizes, that's everything, that's the only reason to use JPEG. And sure, there are many cases where this matters (optimizing bandwidth use on websites for example) but usually it's not worth it)

Since PNG is better should we just stop supporting JPEG? Since PNG and JPEG are better should we just stop supporting GIF? nah. We should support it all and let users decide for themselves, even if they clearly can't make good decisions, it won't make anyone happy if they can't even make a decision at all.

JPEG isn't great for everything, but for things which don't feature lots of abrupt changes in contrast, it still offers a fantastic size/quality/computation tradeoff.

https://people.xiph.org/~xiphmont/demo/daala/update1.shtml

[CrystalGamma]

If people cared about what's best, PNG would be in the most widespread use today. Why isn't it? Because people used JPEG. Why? Just because... (It was the default format of some programs and camera devices)...

Hell, it makes me fucking sick that most digital cameras default to JPEG format and this cannot be configured to PNG output instead. PNG is basically better for everything and should always be used unless filesize is critical (JPEG has stronger compression than PNG resulting in slightly smaller filesizes, that's everything, that's the only reason to use JPEG. And sure, there are many cases where this matters (optimizing bandwidth use on websites for example) but usually it's not worth it)

Since PNG is better should we just stop supporting JPEG? Since PNG and JPEG are better should we just stop supporting GIF? nah. We should support it all and let users decide for themselves, even if they clearly can't make good decisions, it won't make anyone happy if they can't even make a decision at all.

I would actually say a vector format (say, SVG …) would be even better than PNG for most of the purposes mentioned in the comic.
And I probably wouldn't miss GIFs if browsers were to stop supporting them today. On some webpages, I get 3x power usage because there are animated GIFs (which is the only thing GIF has over PNG). Dedicated image viewers obviously should still support them …

[ResponseWriter]

The format conversion is trivial and happens during texture loading. There is no impact while rendering (other than the fact the texture format is different).

Regarding the on-disk shader cache, it really depends on whether it would improve your load times. Have you used a CPU profiler to see where the CPU is spending time?

Haven't yet but can certainly look into it. I am making a bit of an assumption that caching would help as I'm loading from an SSD and using a relatively slow (by current standards) CPU. Loading was much faster with Catalyst (which I found was caching something to my SSD) last time I tried it so there's probably room to improve it somehow.

I recall there was work on an on-disk shader cache by some Intel devs but haven't heard about it for some time. Looks like this is (part of) it: https://patchwork.freedesktop.org/patch/42095/

In progress, I guess.

Thanks for your work on the drivers, BTW. The future of AMD graphics on Linux is looking a lot better for it.

[ResponseWriter]

I would actually say a vector format (say, SVG …) would be even better than PNG for most of the purposes mentioned in the comic.
And I probably wouldn't miss GIFs if browsers were to stop supporting them today. On some webpages, I get 3x power usage because there are animated GIFs (which is the only thing GIF has over PNG). Dedicated image viewers obviously should still support them …

SVGs can be a massive improvement over PNG. It allows me to reduce filesize in some cases and deal with high-DPI displays at the same time. Shame the maker of a certain suite of 'creative' applications hasn't worked out how to give me (or, I should say, let my design give me) SVGs with single lines with stroke applied rather than filled polygons...

[theriddick]

And the article turns into a PNG vs JPEG war. BUT what about TGA and TIFF!

[Delgarde]

And the article turns into a PNG vs JPEG war. BUT what about TGA and TIFF!

Or for photos, RAW... PNG certainly won't do the job when you need to record every bit of detail the camera sensor can give you...