More RadeonSI Navi Improvements Are Pending

[log0]

Can somebody please explain in simple words what those Primitive Shader / NGG actually are for?

From what I read (might got that completely wrong) it is meant to be an early shader
stage that allows culling and discarding stuff early and much more efficiently. (?)

...

For historical reasons there are multiple separate stages (vertex, tesselation, geometry shader) that have to be run before a primitive can be culled or rasterized. Primitive shaders merge these stages and make culling programmable, which allows for early/optimized culling to reduce the number of primitives processed.

The problem is that this merged shader has to be somehow exposed by the API to users. And that is something they are probably struggling with, getting it into directx/vulkan.

[entropy]

For historical reasons there are multiple separate stages (vertex, tesselation, geometry shader) that have to be run before a primitive can be culled or rasterized. Primitive shaders merge these stages and make culling programmable, which allows for early/optimized culling to reduce the number of primitives processed.

The problem is that this merged shader has to somehow exposed by the API to users. And that is something they are probably struggling with, getting it into directx/vulkan.

Thank you!

Yet, if it's an API thing, why does an AMD representative say it's not coming for GFX9 but the next arch (NAVI)?

https://www.mail-archive.com/amd-gfx.../msg24458.html

[skeevy420]

I'm still a bit confused as I don't understand why Fiji/Tonga is separated from Polaris in the new naming scheme if AMD considers them the same generation.

3-1/2th maybe ?

It programs like a 3rd generation part other than a single register bit, but a number of the HW blocks changed to improve performance and save power. From a marketing POV it is reasonable to call it a 4th generation part while from a driver perspective it's still GFX8.

Scroll up? While that's about Polaris, it does answer your question.

[skeevy420]

Thank you!

Yet, if it's an API thing, why does an AMD representative say it's not coming for GFX9 but the next arch (NAVI)?

https://www.mail-archive.com/amd-gfx.../msg24458.html

Perhaps it's a "get it working on the new stuff and backport when that's done" situation?

[skeevy420]

My 1000th post