Cannot disable DSC with UHBR20 on PG32UCDMR

[ello86]

Hello!

Just got my new PG32UCDMR and I love it! Something I noticed though was that I am unable to disable DSC from the OSD even when UHBR20 80Gbps is in effect. 

My setup is HP OEM RTX 5080 DP 2.1  port to PG32UCDMR DP 2.1 port using a VESA certified 2.0m UHBR20 cable. Also, GPU-Z confirms I'm achieving the max bandwidth (20Gbps x 4 lanes). 

I think the PG27UCDM had a similar issue which was fixed in a FW update. Any chance to get this fixed on the PG32 any time soon?

Thanks!

[kampi71]

Me too. I guess we are both on firmware MCM101, right? I just read from a user on reddit, an he reported, that his UCDMR came with MCM102. Overall this seems to be not a real issue, because DSC seems not be activated when you use the DP 2.1 setting, even when it's set on and cannot be disabled. On GPU-Z it shows all 4 lines using 20 Gbps and that indicates 80Gbps and therefore DSC cannot be active. But yeah, a new firmware that fixes and improves things are always welcome. Especially when there is most likely a newer version on several units. I'm a bit suprised by this, because the UCDMR just came out pretty recently.

[ello86]

Mine also came with the MCM101.

I suspect the issue might be related to DSC being negotiated, even when it's not necessary based on the available bandwidth. From what I understand, DSC and UHBR20 aren’t mutually exclusive—so even though 80 Gbps should be more than enough for an uncompressed 4K/10-bit/240Hz signal, DSC could still be enabled. Ideally, DSC could be prevented from being negotiated by disabling it on the display, but that doesn't seem to be working in our case.

[kampi71]

You already mentioned the same issue in previous firmwares of the PG27UCDM and it seems to be the exact same issue with the 32' UCDMR. Besides from that I can say, that I'm pretty pleased with the UCDMR so far. I also own the 32 UCDM which had this super annoying blackscreen issue. Haven't checked this for a while to be honest. Thank god and thx to DP2.1 this is not an issue with the *R" model.

[kampi71 · Accepted solution]

Btw, Asus just released a new firmware MCM103 and now you can disable DSC when using DP 2.1.

[ello86]

Thanks for the heads up! I just upgraded the FW and it does fix the issue. 

[Joel_S]

With a 5080, is the recomended setting off for dsc ?? I did set it to 2.1, and confirmed 20x4 

Just got the monitor a couple days ago.. thanks for your time 

(Updated the firmware right away)

[kampi71]

Yes, I disabled DSC when the new firmware arrived and having absolutely no issues. Well, I also had no issues before to be honest. So, it is 100% safe and because of that, just disable it to be sure, that DSC is off. It's just not needed for DP2.1.