Nvidia Turing Speculation thread [2018]

Discussion in 'Architecture and Products' started by Voxilla, Apr 22, 2018.

Tags:
Thread Status:
Not open for further replies.
  1. Kaotik

    Kaotik Drunk Member
    Legend

    Joined:
    Apr 16, 2003
    Messages:
    8,166
    Likes Received:
    1,836
    Location:
    Finland
    I doubt there will be any sort of dedicated hardware for RT, PowerVR already tried it ages ago without getting any real tractiong (of which I'm aware of)
    The current NVIDIA demos use Tensor cores to accelerate the denoising algorithms (which are used to lighten the load by simply simulating less rays and guesstimating the rest)

    Tensor cores are also where it becomes "tricky" for NVIDIA - they are limited to certain types of calculations which are next to useless at least on current games and I dare to say for foreseaable future too, outside perhaps some special gameworks-shenanigans and the previously mentioned RT (which isn't used in games yet)
    So how much silicon can you really waste on them?
     
  2. trinibwoy

    trinibwoy Meh
    Legend

    Joined:
    Mar 17, 2004
    Messages:
    10,426
    Likes Received:
    423
    Location:
    New York
    Nvidia has been pretty cagey about their DXR implementation. I’ve only seen tensor/AI denoising mentioned in reference to OptiX, not DXR.

    [​IMG]

    I imagine any developer that goes down this path will target general compute performance and not zomg tensors.

    On the other hand DXR performance is going to depend heavily on some secret sauce to speed up acceleration structure construction and ray casting. Microsoft has implemented a DirectX compute based fallback path for hardware that doesn’t have special support for DXR and they expect it to be slowwww. So any useful implementation would presumably require custom hardware.
     
  3. Kaotik

    Kaotik Drunk Member
    Legend

    Joined:
    Apr 16, 2003
    Messages:
    8,166
    Likes Received:
    1,836
    Location:
    Finland
    It's possible I just remember it wrong and/or understood it wrong, but it's hard to imagine what else would explain limiting it to Volta?
     
  4. DavidGraham

    Veteran

    Joined:
    Dec 22, 2009
    Messages:
    2,747
    Likes Received:
    2,511
    Why not? NVIDIA already uses their architectural features to introduce/accelerate special effects in the PC space. Stuff like Ansel, Multi Res Shading/Lens Matched Shading, Single Pass Stereo, and Perspective Surround. These effects are powered by the Simultaneous Multi-Projection (SMT) feature that is only possible due to the PolyMorph Engine 4.0 and the way NVIDIA structures it's Geometry units in Maxwell and Pascal. My guess that RTX could be something similar.
     
    A1xLLcqAgt0qc2RyMz0y likes this.
  5. ToTTenTranz

    Legend Veteran Subscriber

    Joined:
    Jul 7, 2008
    Messages:
    9,827
    Likes Received:
    4,450
    GV104 might not be significantly smaller than GP102.
    With GDDR6 ramping up production, GDDR5X is in an odd place (not as cheap and widely used as GDDR5 + not as fast as GDDR6 + RAM being generally starved of available production lines), so GPUs using it may be EOL'd soon.
    At the same time, 16/12FF isn't a premium process anymore, so making larger chips may be justified.

    By taking away the GDDR5X models, we might end up with a consumer lineup of:

    - GTX 1180 replacing all the GP102 products (1080 Ti + Titan X + Titan Xp)
    - GTX 1170 (cut-down GV104 with 192bit GDDR6 and less SM units) replacing GTX 1080
    - GTX 1070 Ti
    - GTX 1070
    - (everything the same below that)
     
  6. Ike Turner

    Veteran Regular

    Joined:
    Jul 30, 2005
    Messages:
    1,884
    Likes Received:
    1,756
    As already mentioned, as of right now RTX is only "Denoising" using the tensor cores. I've personally confirmed this with devs at Epic who worked on the Star Wars tech demo with ILMxLabs. But as usual Nvidia's PR is all about making it sound like they invented sliced bread. As a matter of fact even Epic devs are "encouraged" to barely mention DXR and instead talk about RTX by Nvidia when discussing UE4's DXR implementation..that's the "price" to pay when you get free HW and help/resources from NV I guess. There's a blog post on Nvidia.com discussion the history of Ray Tracing..and as you guessed it there iqn.t a single mention of DXR in it..RTX on the other hand...

    Example:

    Same video...different names...
    Remedy:

    Nvidia
     
    #186 Ike Turner, Aug 8, 2018
    Last edited: Aug 8, 2018
    Kej, Anarchist4000, Lightman and 3 others like this.
  7. Rootax

    Veteran Newcomer

    Joined:
    Jan 2, 2006
    Messages:
    1,151
    Likes Received:
    571
    Location:
    France
    What type of hardware/calculations do we need to speed up dxr / rtx ? I mean, what is the bottleneck right now ? vram bandwidth ? on chip cache ? raw compute power ?
     
  8. DavidGraham

    Veteran

    Joined:
    Dec 22, 2009
    Messages:
    2,747
    Likes Received:
    2,511
    The tech is still in it's infancy, It's naive to think that's the only part of the pipeline that will ever be accelerated.
    Those very demos are accelerated using hardware provided by NVIDIA, whether we are talking demos from Epic, Dice, or Remedy. All were performed on NVIDIA Volta hardware. Under these circumstances, I don't think it's unusual for NVIDIA to ask for it's name on the box.

    NVIDIA's RTX page actually has more description for DXR than RTX. So it's not really a total obfuscation of the existence of DXR.
    https://devblogs.nvidia.com/introduction-nvidia-rtx-directx-ray-tracing/

    The GameWorks RTX subsection only have RTX denoising at the moment to achieve a variety of effects like Area Shadows, Lights, Reflections and Ambient Occlusion.
    https://developer.nvidia.com/gameworks-ray-tracing
     
    #188 DavidGraham, Aug 8, 2018
    Last edited: Aug 8, 2018
    A1xLLcqAgt0qc2RyMz0y and pharma like this.
  9. trinibwoy

    trinibwoy Meh
    Legend

    Joined:
    Mar 17, 2004
    Messages:
    10,426
    Likes Received:
    423
    Location:
    New York
    Primarily compute and bandwidth efficiency. Building the acceleration structure and casting rays both require lots of random memory accesses and branchy code where different threads/rays in a warp can all be doing their own thing. Each thread can even be running a different shader (depending on what object the ray hits). This doesn't play well with GPUs which thrive on coherent memory access and coherent thread execution.

    Don't think there's a silver bullet. Just need more of everything - flops, bandwidth and huge caches.
     
    Anarchist4000, pharma and Rootax like this.
  10. pharma

    Veteran Regular

    Joined:
    Mar 29, 2004
    Messages:
    2,907
    Likes Received:
    1,607
    Nvidia EEC registrations indicate three new GeForce GPUs
    https://www.guru3d.com/news-story/nvidia-eec-registrations-indicate-three-new-geforce-gpus.html
     
  11. DavidGraham

    Veteran

    Joined:
    Dec 22, 2009
    Messages:
    2,747
    Likes Received:
    2,511
    pharma and nnunn like this.
  12. Geeforcer

    Geeforcer Harmlessly Evil
    Veteran

    Joined:
    Feb 6, 2002
    Messages:
    2,297
    Likes Received:
    464
    How is it possible that the cards are days away from an announcement and such basic things as chip designation and card name, let all me features and specifications are still seemingly unsettled? Did Nvidia hire a bunch of former CIA agents to manage leak prevention or something?
     
    nnunn likes this.
  13. Anarchist4000

    Veteran Regular

    Joined:
    May 8, 2004
    Messages:
    1,439
    Likes Received:
    359
    As trinibwoy mentioned, the issue is in grouping thread branches and coalescing memory access. Assuming a curved surface the rays will diverge horrifically. Essentially looking through a magnifying glass in reverse. Requiring a lot of memory/cache bandwidth to pack a vector for a SIMD unit.

    The silver bullet may be procedural textures and geometry as a method to "compress" the resources and increase effective cache. While there will be some divergence as you mentioned, each thread should be roughly running the same instruction, but with incoherent memory accesses (hall of mirrors).

    A series of cascaded DSPs or FPGA might be more efficient from a hardware perspective as the limiting factor will likely be the memory controller encountering stalls.

    With Volta, Ampere, and Turing it's unclear which part is covering which part the product stack. It's also possible there are minimal changes to the feature set so not worth disclosing for marketing purposes. Sure there is the ray stuff, but I haven't seen anything having to do with higher DX feature tiers and some of those may be problematic as "current" hardware was already supposed to have support or it was "unnecessary". Would be rough to admit hardware accelerated async compute and scheduling.
     
    Rootax likes this.
  14. Samwell

    Newcomer

    Joined:
    Dec 23, 2011
    Messages:
    112
    Likes Received:
    129
    Annoucement is the reason. Nv has a tight control on their partners, so not even they are leaking. So stuff can only leak, when Nvs partners start shipping to distributors. But the hard launch is probably still a month away. But in 3 days we should know a lot more, when they launch/announce the new quadros.
     
    A1xLLcqAgt0qc2RyMz0y and pharma like this.
  15. Rootax

    Veteran Newcomer

    Joined:
    Jan 2, 2006
    Messages:
    1,151
    Likes Received:
    571
    Location:
    France
    AdoredTV just made a video about that :

     
  16. ninelven

    Veteran

    Joined:
    Dec 27, 2002
    Messages:
    1,699
    Likes Received:
    117
    Lol, the conspiracy theory bs at the end....
     
  17. Kaotik

    Kaotik Drunk Member
    Legend

    Joined:
    Apr 16, 2003
    Messages:
    8,166
    Likes Received:
    1,836
    Location:
    Finland
    xpea, pharma and iMacmatician like this.
  18. McHuj

    Veteran Regular Subscriber

    Joined:
    Jul 1, 2005
    Messages:
    1,416
    Likes Received:
    534
    Location:
    Texas
    We'll i'm hoping that the name RTX implies that the GPU actually has some usable features and performance for ray-tracing (if only partial algorithms)
     
    pharma likes this.
  19. Kaotik

    Kaotik Drunk Member
    Legend

    Joined:
    Apr 16, 2003
    Messages:
    8,166
    Likes Received:
    1,836
    Location:
    Finland
    I doubt it's anything more than GV100 already has
     
  20. Malo

    Malo Yak Mechanicum
    Legend Veteran Subscriber

    Joined:
    Feb 9, 2002
    Messages:
    6,972
    Likes Received:
    3,050
    Location:
    Pennsylvania
    And bound to be a lot less?
     
Loading...
Thread Status:
Not open for further replies.

Share This Page

  • About Us

    Beyond3D has been around for over a decade and prides itself on being the best place on the web for in-depth, technically-driven discussion and analysis of 3D graphics hardware. If you love pixels and transistors, you've come to the right place!

    Beyond3D is proudly published by GPU Tools Ltd.
Loading...