OpenGL & Vulkan

[onsolight]

Vulkan 1.1.110 Released  will RX 480 support the following extensions anytime soon?

VK_EXT_fragment_shader_interlock - Featured in Vulkan 1.1.110

GL_ARB_fragment_shader_interlock - Part of OpenGL 4.5

i'm a bit disappointed and curious as to why Nvidia and Intel has support for this but AMD doesnt.

[dipak]

Our OpenGL & Vulkan forum seems to be better place to ask this query, so I'm moving it there.

Thanks.

[dorisyan]

Hi onsolight‌, Thanks for your feedback, It looked like we didn't support this ext, we will take it into consideration. Thanks!

[onsolight]

Is Polaris even capable if it? Im seeing allot say only Vega supports the feature.

[dorisyan]

I haven't got the exact message until now

[onsolight]

Any news on this? looks like Nvidia already has support for it.

[gharland]

onsolight, could you check with gl extension viewer if your 480 supports

GL_INTEL_fragment_shader_ordering

it reports the R VII does have support 

[onsolight]

nope nothing here

[gharland]

if the hardware doesn't support it, maybe they can emulate it in software.  Hopefully it would only cause a slowdown in the event of concurrent writes to the same pixel, which may only be a small proportion of fs invocations.  Better to lose a few fps than not be able to run at all.  Fingers crossed.

[onsolight]

would it be worth it is the thing how much of an impact would it make?

[gharland]

I'm not an expert on how the hardware works but If the slowdown is significantly more than the 2-3x slowdown you get from spinlocking or k-buffers, then maybe not.  But could be potentially faster than or close to the same speed as native atomics, which would be a huge win.  It would make life a hell of a lot easier for developers either way.  If I'm right about only in the event of concurrent writes to the same pixel, I doubt you'd even notice it - especially in the context of an emulator - it would just be a memory fence for that pixel quad or wavefront.  I think in the case of programmable blending for emulators which I know nothing about it's also a case of everybody gets it or nobody gets it.  It would be nice to have the option.

[dorisyan]

Hi all，

We are discussing about this extension, I will give you feed back soon.

[onsolight]

Updated to 19.7.3 and Vulkan API is 1.1.113  any update on this?

[dorisyan]

Recently, I didn't see updates about shader interlock.

[onsolight]

oh i see. ill return to my corner and weep 

[zinx · Accepted solution]

Looks like the answer is no:

Expose primitive ordered pixel shaders · Issue #108 · GPUOpen-Drivers/AMDVLK · GitHub 

[onsolight]

dorisyan‌ should i take this as a reason to drop AMD and hop on the Nvidia Train?