HDMI 2.1 Bug Is Glitching 4K 120Hz Support on Nvidia Ampere GPUs and Xbox Series X

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AV receivers are the perpetrators

According to a report from heise.de, a German news outlet, a bug in HDMI 2.1 outputs on select AV receivers is causing black screens when enabling 4K 120Hz capabilities on Nvidia's Ampere graphics cards or Microsoft's Xbox Series X.

As it turns out, this issue specifically impacts HDMI 2.1 chips from Panasonic, which are installed in Denon, Marantz, and Yamaha AV receivers. For some reason, the chips cannot display the 4K resolution at 120Hz without errors with specific hardware, like the Ampere GPUs and Microsoft's upcoming console.

Fortunately, the issue seems hardware-specific, other gaming devices like the PS5 seem to function perfectly fine. For now, the solution is to reduce your resolution and/or refresh rate to HDMI 2.0b standards (4K 60Hz). Another fix is to connect your AV receiver to your TV's eARC HDMI port and connect your affected device to the TV. This way the AV receiver only deals with processing audio while the TV handles everything else.

New fixes are underway, and Panasonic should be manufacturing new HDMI 2.1 chips that are free of this bug by the middle of 2021. Unfortunately, this also means you'll need to replace your AV receiver if your unit is bugged, and you can't use any of the workarounds already mentioned.

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Aaron Klotz
Aaron Klotz
Contributing Writer

Aaron Klotz is a contributing writer for Tom’s Hardware, covering news related to computer hardware such as CPUs, and graphics cards.

7 Comments Comment from the forums
  • ThisIsMe
    I haven't seen anything anywhere stating for a fact that the PS5 is not impacted by this. The only reason the main story mentioned the Series X and the RTX2080 is because they actually had them to test. It will likely affect the PS5 as well, at least to some degree, considering the chips in the receivers do not correctly support the full HDMI 2.1 spec. Most sites are speculating the chips only correctly implement the slower compressed signal rates and not the fastest uncompressed signals. It's also important to note that the chips were supplied by Panasonic Solutions, not by Panasonic.
    Reply
  • watzupken
    In my opinion, this is almost a non-issue for consoles. At least what we have seen so far, both consoles generally run up to 4K @ 60 FPS/60Hz in games. Unless of course you are looking at those less graphic intensive/ Indie titles. So essentially there's not much point in enabling 4K @ 120Hz.
    Reply
  • gsxrme22
    The PlayStation 5, Xbox Series X and the rtx3000 series are all affected. The problems not the graphics card that chip you mentioned in your article has nothing to do with the gaming consoles or graphics cards but the chip actually resides inside of the television sets. All of the new consoles as well as graphics cards require a uncompressed signal to reach 4K at 120 HZ and unfortunately Panasonic made a chip that requires a compressed signal. Meaning there's no TV in the world at the moment I could do 4K at 120 hertz to an HDMI port due to Panasonic's chips and the televisions.....
    Reply
  • emayekayee
    I was looking into all of these receivers as an option but decided that the best way to future proof my audio set up was to wait one more year for full HDMI 2.1 implementation on less expensive models. Glad I dodged that bullet. A lot of the 4k/120 receivers were already a little out of my price range. I would have been pissed had I gotten one and found out that feature was bugged and not repairable. I wonder if any of these companies will do the right thing and replace/refund these receivers.
    Reply
  • emayekayee
    gsxrme22 said:
    ..... Meaning there's no TV in the world at the moment I could do 4K at 120 hertz to an HDMI port due to Panasonic's chips and the televisions.....


    It's not an issue with the TVs. It's AV Receivers. There are dozens of TV models this year that can display a 4k 120Hz signal. If you're not running through one of those AVR models, there's no problem.
    Reply
  • mac_angel
    ummm. If you do a bit of research, you know that it is not "for some reason".
    There are two different types of signals for 4k 120Hz. Compressed or non-compressed. Panasonic's chips only handle the compressed format, while PS5, xBox-X, and RTX 3080 use non-compressed signals.

    "If you’re into the technical side of video transmission, you might be wondering whether compression is used to achieve these high resolutions and frame rates in the HDMI 2.1 specification. The short answer is maybe. The spec supports both compressed and uncompressed modes, leaving it up to the individual manufacturers to decide which mode(s) to implement. " Audioholics.com

    No one seems to know who is at fault. HDMI Forum’s Technical Working Group are suppose to have set standards for something to have the full HDMI 2.1 license. But I haven't been able to find a copy to read. You have to be part of the HDMI Adopter group to have access to downloading it.
    The bug is from uncompressed vs compressed signal not being compatible, which seems rather obvious. And obvious that the two aren't going to be compatible with each other, as well as obvious that to get a license, they shouldn't have the option of "either or", but for both. HDMI is suppose to be universal. You can't give companies options of "either or" on things that are not going to be compatible with each other. I'm really surprised about the HDMI TWG were so lax on this thing. Giving companies an option that are incompatible with each other is just setting it up for something like this to happen.

    Side note. I'm rather curious about how VRR would transfer through an AVR as well. To me, the so called "work around" seems like a much better way to go to begin with, especially on a performance/lag standpoint - Hooking up the console or computer directly to the TV and using eARC for the audio.
    Reply
  • gsxrme22
    Im not paying $2k+ OLED for a work around. Hdmi 2.1 is the only HDMI ever to use compression (DSC 1.2) I smell lawsuits!
    Reply