What changes did nvidia make to HDCP or DSC a few drivers back? Who is at fault?

Discussion in 'Videocards - NVIDIA GeForce Drivers Section' started by PittyH, Feb 11, 2021.

  1. Astyanax

    Astyanax Ancient Guru

    Messages:
    10,313
    Likes Received:
    3,705
    GPU:
    GTX 1080ti
    Unrelated to DSC, this is in relation to DP++.
     
  2. janos666

    janos666 Master Guru

    Messages:
    995
    Likes Received:
    159
    GPU:
    MSI RTX3080 10Gb
    Related to DP 1.4(a) to be more precise. The ++ part has to do with passive DP->HDMI converters (such as this for example, where the DP port natively switches to HDMI signaling and all the converter does is voltage level conversion without active signal processing). The DP 1.4 -> HDMI 2.1 active converter doesn't use the ++ capability of the DP interface (that remains in DP mode rather than switching to HDMI mode). Note that as of DP 1.4(a) the ++ mode only allows for up to standard HDMI 2.0 TMDS clock (you won't find passive adapters officially supporting HDMI 2.0 but 1.4 only, although those 1.4 adapters work just fine for HDMI 2.0 as well as soon as you apply the higher TMDS clock limit by driver patching - but FRL or "overclocked TMDS" [above 2.0 clocks] are not possible). Also, the Club3D converter sadly lacks the VRR feature of HDMI 2.1 and DP 1.4a, so everyone's best bet (with an VRR capable HDMI 2.1 device) is an Ampere card (regardless of their practical prices and availability) regardless of any driver/firmware bugs.
     
  3. Astyanax

    Astyanax Ancient Guru

    Messages:
    10,313
    Likes Received:
    3,705
    GPU:
    GTX 1080ti
    Correct, though the point was that its specific to passive adapters which the Club3D is certainly not
     
  4. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    So this won't fix not being able to get 4k120hz on the newer drivers through the CAC-1085?

    hmm bummer.
     

  5. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    Last edited: Mar 9, 2021
  6. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    Astyanax,

    How do you know this is related to DP++?

    Where does it say that anywhere?

    Manuel posted that in https://www.nvidia.com/en-us/geforce/forums/notifications/topic/182605/ this topic regarding CAC-1085

    "I added the bug to the open issues section of the 461.40 driver feedback thread."

    Which is Displayport-to-HDMI 2.1 protocol converter clock limited to 600MHz pixel clock [3202060]

    I fail to see how you think it's related to DP++, but you are an ancient guru, and I don't know much about it all.

    I just want to able to get 4k120hz on the last 6 driver versions.
     
  7. Astyanax

    Astyanax Ancient Guru

    Messages:
    10,313
    Likes Received:
    3,705
    GPU:
    GTX 1080ti
    Actually, theres a bunch of confusing things about whats going on with the CAC adapters, the conversion is supposed to be completely transparent to the graphics card with it believing it should be talking to a DSC enabled display, but the bug title seems off. the protocol clock that DP uses isn't directly related with the pixel clock.

    a) DP doesn't itself have a pixel clock, the device doing the protocol conversion is responsible for providing the pixel clock.

    b) DP++ passive hdmi output (2.0 max), would be the graphics card (currently adaptable only to 594Mhz by design and specification)

    c) HDMI 2.1 does not use TMDS, so the pixel clock is irrelevant (the only reason the resolution creator even mentions it is a legacy hdmi holdover).

    For whatever reason, the adapter is not reporting dsc capability to the driver unless the tv supports the hdmi 2.1 dsc spec.

    Club3D should patch their firmware to spoof DSC support from the TV end.
     
    Last edited: Mar 13, 2021
  8. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    Could any of this be fixed with CRU?
    on 456.71 or later drivers, I lose the ability to select 4k 120hz in the nvidia cpanel.
    in CRU, they have a new options menu which shows this below.

    On the right hand are a few options, I messed around with it a bit so these ticks weren't default I think.
    I played around with it a bit, but none of it will allow 4k120hz on the above mentioned drivers (even though 4k120 is a listed resolution in CRU) just not in nvidia cpanel.
    Nvidia cpanel just doesn't want to do 4k120 10/12 bit anymore - if I create a custom 4k120 resolution in nvcpanel the color depth can't be changed.and some funky things start happening like it's 4 bit colour or something.

    [​IMG]
     
  9. Astyanax

    Astyanax Ancient Guru

    Messages:
    10,313
    Likes Received:
    3,705
    GPU:
    GTX 1080ti
    I would deselect the tmds character rate as its not relevant to hdmi 2.1, and check DSC 1.2a (i think every option under that box is reliant on the first checkbox)
     
  10. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    OK thanks trying to do things by the book to troubleshoot.

    This is a brand new install of 461.72 - and these are the default options - as you can see i have no 120hz option under pc settings, and only 60hz under Ultra HD/HD/SD.

    But the option is there under CRU listed resolutions.
    Those are also the default HDMI 2.1 settings as listed in CRU with 461.72.

    Do the nvidia drivers affect any of the CRU settings (like if I installed the older nvidia drivers the CRU settings would remain the same.

    [​IMG]
     

  11. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    I will now attempt your recommended settings

    Ok well I tried the settings, but still no 4k120hz option under nvidia cpanel.

    Not sure what to do, the 4k120hz resolution is listed in CRU, but not in nvidia cpanel.
     
    Last edited: Mar 14, 2021
  12. PittyH

    PittyH Member

    Messages:
    39
    Likes Received:
    3
    GPU:
    2080ti
    ToastyX replied over on monitortests, stating the same thing, Nvidia bug

    Guess I will just have to go back to 456.71

    Thought CRU could fix it somehow. :(

    Looking forward to the day when 4k120hz and 10 bit color with HDR and VRR just works out of the box. When Windows, Nvidia and LG and Games companies can all get on the same page. heh, seems we're not quite there yet
     

Share This Page