On Ray-Tracing... What Do RTX Cores Even DO!?

[bmichaels556]

So this is my 10,000 foot level understanding of what ray-tracing is, how it works, and how Nvidia cards are driving it now. One thing that seems to be happening is that RTX cores merely ACCELERATE ray-tracing, and aren't respomsible for a card being able to do it per se, correct? My evidence for this, is that even when ray-tracing, the cards still lose performance, which sounds like it's so demanding that it's cutting sharply into the rest of the card. Or something like that? 

 

Now, I could again be totally off, but aren't other Nvidia cards now able to ray-trace without RTX cores using some kind of generic method in DX12? So if that's the case, why can't AMD cards do the same thing right here, right now? Has it been specifically adapted to Nvidia's hardware and so isn't quite ready to be able to run on other cards? 

 

Regardless, it all just sounds like RTX was a brilliant scam that was all marketing and no substance. I guess I'm preaching to the choir on that one though. But it seems like the equivelent of selling 8K TV's when 4K content was hardly available a number of years ago. This latest and great thing that does absolutely nothing for the user. Not well, anyway.. Pretty much snake oil until it reached potential. 

 

This is sort of a rant, but I'm also looking for a little more info how other cards are able to ray trace without RTX, and also why AMD cards are not able to do it currently, or maybe ever on what's currently out there.

[unsungheroist]

9 minutes ago, bmichaels556 said:

So this is my 10,000 foot level understanding of what ray-tracing is, how it works, and how Nvidia cards are driving it now. One thing that seems to be happening is that RTX cores merely ACCELERATE ray-tracing, and aren't respomsible for a card being able to do it per se, correct? My evidence for this, is that even when ray-tracing, the cards still lose performance, which sounds like it's so demanding that it's cutting sharply into the rest of the card. Or something like that? 

 

Now, I could again be totally off, but aren't other Nvidia cards now able to ray-trace without RTX cores using some kind of generic method in DX12? So if that's the case, why can't AMD cards do the same thing right here, right now? Has it been specifically adapted to Nvidia's hardware and so isn't quite ready to be able to run on other cards? 

 

Regardless, it all just sounds like RTX was a brilliant scam that was all marketing and no substance. I guess I'm preaching to the choir on that one though. But it seems like the equivelent of selling 8K TV's when 4K content was hardly available a number of years ago. This latest and great thing that does absolutely nothing for the user. Not well, anyway.. Pretty much snake oil until it reached potential. 

 

This is sort of a rant, but I'm also looking for a little more info how other cards are able to ray trace without RTX, and also why AMD cards are not able to do it currently, or maybe ever on what's currently out there.

The first implementation of a "real-time" ray-tracer was the LINKS-1 Computer Graphics System built in 1982 at Osaka University's School of Engineering, by professors Ohmura Kouichi, Shirakawa Isao and Kawata Toru with 50 students. so in short yes.

only accelerate 

[Princess Luna]

[TheKDub]

13 minutes ago, bmichaels556 said:

One thing that seems to be happening is that RTX cores merely ACCELERATE ray-tracing, and aren't respomsible for a card being able to do it per se, correct?

Correct. Dedicated hardware is in no way necessary for path traced light simulation, however it certainly helps, that way the load isn't being put onto your main GPU cores instead.

[Jurrunio]

The short answer is "a type of math it does better than CUDA cores"

[Eigenvektor]

13 minutes ago, bmichaels556 said:

One thing that seems to be happening is that RTX cores merely ACCELERATE ray-tracing, and aren't responsible for a card being able to do it per se, correct? My evidence for this, is that even when ray-tracing, the cards still lose performance, which sounds like it's so demanding that it's cutting sharply into the rest of the card. Or something like that?

Correct, they accelerate it.

 

In fact, it is so demanding that even with RTX cores, the GPU is not raytracing every pixel on screen. They are only tracing some rays and then using machine learning to fill in the rest.

[Do you really wanna know]

AMD GPUs can ray-trace, its just they are not programmed to, because in doing so you would halve the frame rate... Oh hang on....

 

On the other side of the coin you shine a light on, I used to ray trace Mandelbrot sets on my old Sinclair Spectrum (48K total memory), with a 3.5 Mhz CPU - Yes 3.5 Mhz!

 

It took 24 hours+ to render the frame (yes a single frame, not frames), and another 24 hours+ to ray trace that frame, but RTX not needed then, nor now!

[Vishera]

Well,you can do real time ray-tracing on any processor if the software support for it exists,even CPUs,the only difference is performance,

Dedicated hardware will perform significantly better than the rest.

Also considering that Turing was optimized for real time ray-raced workloads,Non RTX Turing GPUs perform better at real time ray-traced workloads than Pascal.