[SOLVED] Can't get more than 80 Hz in 4K HDR on a PG43UQ from a Quadro RTX 5000 laptop?

[Quaternion]

The title pretty much says it all. I recently got a Lenovo P15 laptop since I'm going to be traveling a lot more in the future. The laptop has two Thunderbolt 3 ports. I checked the model number of the Thunderbolt 3 controller inside, and according to Intel ARK it should have DisplayPort 1.4 support. The Quadro RTX 5000 is built on the Turing architecture obviously, which should mean that it supports DSC, so 4K 144Hz HDR should be totally feasible, but my Asus PG43UQ loses signal permanently when I set it above 80Hz with HDR enabled. DisplayPort revision is set to 1.4 and DSC is enabled in my monitor's OSD settings. Any suggestions?

Misc. Details:

• The Quadro is the component acting as the display adapter, not the integrated graphics. I am sure of this.
• In the "advanced display settings" pane of Windows Settings, bit depth is always listed as 10-bit, regardless of whether the color space is listed as SDR or HDR.
• I can get up to 120Hz in 4K HDR if I select YCbCr 4:2:2 (chroma subsampling) in the Nvidia control panel.
• I can get a full 144Hz in 4K SDR.
• I can get up to 80Hz in 4K HDR if I select either RGB 4:4:4 (default) or YCbCr 4:4:4.
• I can't get more than 60Hz using my laptop's HDMI port. This was expected, though, as it's HDMI 2.0.
• I don't believe that the full/limited range setting in Nvidia control panel has any effect on the outcome, but I didn't test it thoroughly.
• Do I need to manually turn on DSC somehow?

 

[kerberos_20]

thunderbolt (titan ridge) indeed supports dp 1.4 with dsc
since ure able to select in gpu settings resolutions/modes which just doesnt display on your monitor, then fault should be between tb3 port and monitor (cable/adapter)
if ure using cable provided with monitor, than it remains tb3 to dp adapter (docking station counts as adapter aswell)
does your thunderbolt adapter supports dsc?

 

[Quaternion]

thunderbolt (titan ridge) indeed supports dp 1.4 with dsc
since ure able to select in gpu settings resolutions/modes which just doesnt display on your monitor, then fault should be between tb3 port and monitor (cable/adapter)
if ure using cable provided with monitor, than it remains tb3 to dp adapter (docking station counts as adapter aswell)
does your thunderbolt adapter supports dsc?

I got the cable from Amazon specifically for this setup about a month ago. Claims to be DP 1.4. Cable Matters

 

[kerberos_20]

that cable says "enjoy 4K at 120Hz", while no mention about DSC, cable needs to be VESA certified for DSC

if there is DSC supported, then product description would be telling it
here some cable with adapter example
https://www.startech.com/en-us/audio-video-products/cdp2dp14b

VESA Certified DisplayPort 1.4 Cable - 8K 60hz Ready

Cable Matters DisplayPort 1.4 cable is an indispensable companion for the latest computers and monitors equipped with DisplayPort.

www.cablematters.com

 

[kerberos_20]

so looking at it at deeper level, DSC is using FEC forward error correction which is same as ECC inside server RAM, without it encoded data will get corrupted

here some reading on anadtech wwhich explains DSC
https://www.anandtech.com/show/1011...-14-standard-displayport-adds-compression-hdr