AMD: Navi Speculation, Rumours and Discussion [2019-2020]

Wasn't this supposed to be shown at GDC (before it dies, that is)?

 

They must have messed up the upload or something as that video file they have is internally 24 fps for the AMD RDNA 2.0 RT demo.
Frame cadence is 3 frame repeat, 2 frame repeat, 3 frame repeat, 2 frame repeat.

 

Wait whaaaat! Can please someone explain something to me? At the end of the video, the two large curved surfaces on both sides of the robot. Why don't the reflexions on different segments align at all, when the surface does seem to align perfectly? That looks like cubemap reflexions, not like RT reflexions at all. Fishy as hell!

 

... nice dose of programmer porn. Although it's nothing new since Turing.

Did not get all the details about usage of inline tracing here, but i assume the proposed uber shader aproach is just the obvious optimization for reflections on any hardware.
Remembering high cost of RT in BFV, i assume it is because they have many different material shaders and hit shading ends up with very bad threads utilization because only few rays of a wavefront end up on the same material shader, and we get serialization instead parallelization. I guess they had no time to make an uber shader for all their content, and this was the reason they have less than one ray per pixel.
That's pure guessing, but even if a GPU has HW support to bin hits per material, uber shader for most stuff should end up faster. Ofc. uber shader causes more complexity and branches than multiple simpler shaders, and constrains content creation.

But aside of that, i would not wonder if NV and AMD have very different sweetspots in using inline vs. shader based RT.

Very intersting: SX supports tracing meshlets!

uuh... let's hope AMD RT is not too 'cinematic' then.

 

Bunch of demos like that lately, the footage from Minecraft pathtracing demo is also screwed up because they had an unlocked framerate, so skip skip skip.

I'm not sure these demos were necessarily meant to be recorded but the virus suddenly made it necessary, so a bunch of people without good demo recording knowledge (v-sync, keep your frame pacing!) suddenly have to record all this. Just a guess for this RT demo though.

 

Yeah, all this stuff was definitely made for GDC, which went kaput.
At least they showed thingies.

 

Is that AMD RT video serious? It's not some subtle and knowing nod to the thread-of-gold on this site about chrome-plated T-Rexes?

Was the art director 12 years old or something?

 

At least they did not show hot robo girl like Adshir did.
Which proofs they know at least a bit about what's a total no-go nowadays

 

I'm pretty sure there was two directives:

1. Show off-screen stuff in reflections
2. Make everything shiny and reflective. That spongebob episode in the future where everything is chrome? That's what we want.

 

Is it me or just the video encoding quality, but the reflected parts of the scene seem to be lower res as well as having no reflections in reflections.

 

No it's not you, in the presentation they state they use half res for reflections, as well as single shader pass, (which probably means one reflection pass only).

 

Plus or minus a few frames ... Is the demo on a RDNA 2.0 console or gpu?

https://www.tomshardware.com/news/amd-directx-raytracing-demo-rdna-2-gpu

 

A slide I thought was pertinent:




AMD is rumored to be claiming an "IPC" increase, as well..

 

Yeah RDNA2 is the first time they've been applying their super-sleek CPU design methodologies to GPUs.

 

Only some SRAM macros iirc.
That's not even remotely relevant to their design methodologies but still.

 

The XBox Series X intersection engine (RDNA2) can do 380 billion intersections per second. So how many rays per second can it do?

 

Just another "big number" that GPU vendors throw around. Gigarays a second, verts a second, whatever. Deducing any real world performance from "big number" is always just random feeling, it's not very useful beyond "sounding big!".

 

It means something if both gpus are essentially the same. It's like saying a gtx1080 isn't necessarily better than a gtx1070 just because it has bigger numbers. I do think games will scale very well between the two gpus, and with diminishing returns on resolution the differences will be harder to spot than ever.