RX480 4k@60Hz over HDMI, fundamentally broken?

Joined
Nov 30, 2016
Messages
19
Backstory: a few months ago I got two LG 27UD68 4K FreeSync monitors for a good price to replace my old 1440p Aurias with big ugly plastic bazels. My R9 290 didn't have proper outputs to drive 4K at 60Hz so since I don't game that much anymore I also got RX 480 (MSI Gaming X model). I tried DisplayPort which worked flawlessly, except putting my monitors to sleep resets desktop as described here https://hardforum.com/threads/turning-off-displayport-monitor-resets-desktop.1714330/ and here https://hardforum.com/threads/stop-windows-auto-detection-madness.1783558/

I couldn't live with having to rearrange my desktop multiple times a day, so in desperation I decided to use HDMI. Howevcer, the universe seems to be conspiring against me and after having tried everything, and I mean everything, I can only come to conclusion that HDMI 4K@60Hz must be broken on RX480, either hardware, or software. My problem is that using HDMI at 4K@60Hz results in random signal loss and occasional display artifacts every so often. This is how it looks:


I have tried everything, and I do mean everything to fix it. I have tried different 480 (Asus Strix RX 480), I have bought some really expensive HDMI cables including bluejeans HDMI cables at $20 a pop thinking it's some kind of interference and better cable would help, it didn't. I have tried switching output from RGB to YCbCr and vice versa, I have tried hooking up just one monitor to the card, I have tried borrowing another 27UD68 monitor from my dad to see if maybe both of my monitors are defective (they aren't, a third LG 27UD68 had the same problem connected to my RX480), I have religiously installed every new driver from AMD thinking it would help, I have tried doing "Clean Install" through AMD driver installer, I have tried DDU utility. Nothing helps.

In the meantime it looks like I'm not the only one having this problem. There are multiple people at AMD community complaining about the same problem:
https://community.amd.com/thread/205187

The only thing that I found that solves the problem is going into monitor properties and changing refresh frequency to 59Hz or 60Hz, then I get zero signal loss, but this is a temporary solution, it only works until next time my monitors go to sleep, so I'm stuck with fiddling with refresh setting in my windows every time I want to use my PC.

Has anyone encountered something familiar with RX 480? Does anyone have RX 480 successfully driving 4K at 60Hz in 4:4:4 profile?
 
Joined
Jun 23, 2015
Messages
14
How long is your HDMI cable and is it certified for HDMI 2.0 Specifications? I have a 4K monitor running at 60Hz just fine with a RX 480 with HDMI Connection.
 
Joined
Nov 30, 2016
Messages
19
Yeah, the cables were "Premium Certified" which means they are guaranteed to carry 4K@60Hz signal, and they were no longer than 6 feet. I've tried multiple cables too, I've tried cables that came with the monitors, I've tried really thick 24AWG cables, I've tried active RedMere cables, I've tried plain monoprice "Premium" cables, I've even coughed up and purchased super expensive bluejeans Premium cables. Nothing worked.

I guess there is some sort of wide spread incompatibility between RX480 HDMI output and various 4K displays as evidenced by the thread at https://community.amd.com/thread/205187 and I just happened to be one of the lucky ones.

In the end I did solve my problem. I ordered two passive DP to HDMI cables and so far they seem to work. No more signal loss and no more rearranging/resizing applications when my monitors go to sleep. The only downside is that Freesync doesn't work, but right now I'm happy I don't have to rearrange my windows every time my monitors wake up and that I don't have to deal with displays spazzing out on me. My next set of monitors is probably going to be HP ones since they tend to have DP hot plug detect feature. Sigh... stupid technology, why won't you work like you're supposed to?
 
Last edited:

Namx01

Weaksauce
Joined
Feb 4, 2008
Messages
67
Yeah, the cables were "Premium Certified" which means they are guaranteed to carry 4K@60Hz signal, and they were no longer than 6 feet. I've tried multiple cables too, I've tried cables that came with the monitors, I've tried really thick 24AWG cables, I've tried active RedMere cables, I've tried plain monoprice "Premium" cables, I've even coughed up and purchased super expensive bluejeans Premium cables. Nothing worked.

I guess there is some sort of wide spread incompatibility between RX480 HDMI output and various 4K displays as evidenced by the thread at https://community.amd.com/thread/205187 and I just happened to be one of the lucky ones.

In the end I did solve my problem. I ordered two passive DP to HDMI cables and so far they seem to work. No more signal loss and no more rearranging/resizing applications when my monitors go to sleep. The only downside is that Freesync doesn't work, but right now I'm happy I don't have to rearrange my windows every time my monitors wake up and that I don't have to deal with displays spazzing out on me. My next set of monitors is probably going to be HP ones since they tend to have DP hot plug detect feature. Sigh... stupid technology, why won't you work like you're supposed to?


Just found this, not sure if it is exactly what you need but it looks interesting.

http://monitordetectkiller.com/
 
Joined
Nov 30, 2016
Messages
19
Just found this, not sure if it is exactly what you need but it looks interesting.

http://monitordetectkiller.com/
Yeah, I came across those while looking for solution to my problem, however these adapters are only for HDMI and they are intended to solve a problem that I have never had.

As I said, I got a pair of DP to HDMI cables yesterday evening, and so far I have had zero signal drops, so hopefully my problems are fixed.
 
Last edited:
Top