XZ342CK Refresh Rate Max'ed out at 60hz/3440x1440 using USB-C to DP

WTFJC
WTFJC Member Posts: 3 New User
in Monitors

Hi,

I am a new owner of a XZ342CK P 34” ultrawide monitor (rated at 144hz @ 3440x1440 w/HDR). The display is very nice but I cannot set the refresh rate to anything higher than 60hz at 3440x1440 resolution (with HDR) using an USB-C to DisplayPort cable (cable is rated at 8K/60hz). This is strange as I was able to get 100hz at 3440x1440 using my old monitor (MSI MAG341CQ no HDR), so I believe my laptop’s USB-C port is capable of at least 100hz at 3440x1440.

Any idea why that I can’t do better than 60hz using USBC-DP with the new monitor? Separately, I also tried an USB-C to HDMI cable and I was able to set the refresh rate to 100hz at 3440x1440 but HDR is no longer available.

My laptop is a Dell Inspiron 5570 with an Intel UHD 620 graphics chipset. I’ve also updated the monitor driver.


Any advice is greatly appreciated, and thanks in advance.

Jim

Answers

  • Leostat
    Leostat ACE Posts: 3,043 Pathfinder
    It could be reading the EDID table from the monitor and limiting it to that, does the laptop have the intel graphics centre? If so you may be able to force it to 100hz by creating a custom res
  • billsey
    billsey ACE Posts: 34,228 Trailblazer
    More likely it's a limitation of Dell's implementation of the UHD 620 output over USB-C. They are using too much bandwidth in HDR mode to support the higher refresh. With HDR disabled it should work at 100Hz, and likely at 120Hz or 144Hz as well.
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.
  • WTFJC
    WTFJC Member Posts: 3 New User
    Leostat said:
    It could be reading the EDID table from the monitor and limiting it to that, does the laptop have the intel graphics centre? If so you may be able to force it to 100hz by creating a custom res

    Thanks, Leo. I was able to get the refresh rate up to 92hz using your suggestion:


    It wouldn't go any higher but it's a significant increase nonetheless. Thanks for the tip.
  • WTFJC
    WTFJC Member Posts: 3 New User
    billsey said:
    More likely it's a limitation of Dell's implementation of the UHD 620 output over USB-C. They are using too much bandwidth in HDR mode to support the higher refresh. With HDR disabled it should work at 100Hz, and likely at 120Hz or 144Hz as well.

    Thanks, Bill. I always had HDR set to Off.



    That said, Windows would always turn HDR back on automatically whenever I play HDR content. I am not aware if there is a way to turn disable it permanently.
  • Leostat
    Leostat ACE Posts: 3,043 Pathfinder
    Good point on the HDR I hadn't considered the bandwidth used by that! 

    As for why it's turning it on, I thought that option prevented the display from switching, is there an option in the monitor osd to turn it off? 

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