RX 6800 nitro+ HDMI issues + not working HDMI 2.1 VRR with LG C9 + high idle power at 4k 120 Hz

Pabaisa

Weaksauce
Joined
Oct 22, 2013
Messages
81
Hi, to begin with everything was ok (1080 ti) before changing to RX 6800 but now:
1. Changing anything related to HDMI (pulling HDMI cable, plugging HDMI cable, changing instant game response setting in LG C9, turning on LG C9 after I turn it off with active windows screensaver (TV shows no signal message and PC restarts after ~4 seconds) simply restarts whole PC with no error codes in Event manager. Any though on that? I have 2 certified HDMI 2.1 cables and there is no change in behavior at either 60 or 120 Hz. There are no problems (working from home so using pc for around 12 hours everyday) if I do not change anything (do not change LG C9 settings, do not turn it off, etc.)
2. Anyone knows anything about AMD HDMI 2.1 VRR status at the moment? As far as I know it is not working because in far reaches of the web I did not find anyone who got HDMI 2.1 VRR working (not freesync but HDMI 2.1 VRR). Having LG C9 I can assure you that AMD drivers do not display option to turn on VRR (freesync EDID override does not work because LG C9 does not receive signal after doing it (did the same mod on my 1080 Ti and TV worked 100% just, obviously, did not have freesync).
3. More of a rant really (other RX 6800 (XT) and LG CX or C9 owners input would be appreciated) because official AMD response (to, as far as I'm aware, a known issue) was to try card in a different system – RX 6800 memory speed at 4k 120/100 Hz is at 100% (2000 Mhz) whick not only increases idle power draw from 7-9 W (at 60 Hz) to ~39 W (at 100/120 Hz) but also heats up card quite well.

AMD does not make it easy to like them... Still waiting for a friend to finish Cyberpunk so we can change cards (he has 3080) so I can enjoy metro exodus with ray tracing.
 
Last edited:

Snowknight26

Supreme [H]ardness
Joined
May 8, 2005
Messages
4,263
Can't comment on the other two, aside possibly needing to change the input name on the C9 to 'PC', but as far as #3 goes, that is unfortunately normal behavior. The memory clocks speeds don't have enough time to change during the vertical blanking period. You can perhaps try using CRU (Custom Resolution Utility) to find a set of frequencies that works with your particular display, but don't have high hopes. The same thing happens for people using high refresh rate multi-monitor setups, so I imagine a single 3840x2160 display at 100Hz/120Hz will exhibit similar behavior due to the amount of bandwidth required. It's not limited to just the RX 6800 or AMD cards.

There are lots and lots of thread about #3, but here are just a few examples (mostly related to the RX 5700 XT as that's what I was specifically searching for):
https://www.reddit.com/r/Amd/comments/k92b2x/psa_if_you_have_a_144hz_monitor_check_your_gpu/
https://www.nvidia.com/en-us/geforc...ards/5/414262/rtx-3090-high-idle-power-usage/
https://www.reddit.com/r/Amd/comments/i09h9o/need_a_fix_for_memory_clock_being_locked_at/
https://www.reddit.com/r/Amd/comments/7x9rln/problem_with_2_monitors_gpu_gets_warm_and_memory/
https://community.amd.com/t5/graphi...eter-allows-gpu-vram-frequency-to/td-p/318483
 

BomTarnes

n00b
Joined
Jan 18, 2021
Messages
1
Hi, to begin with everything was ok (1080 ti) before changing to RX 6800 but now:
1. Changing anything related to HDMI (pulling HDMI cable, plugging HDMI cable, changing instant game response setting in LG C9, turning on LG C9 after I turn it off with active windows screensaver (TV shows no signal message and PC restarts after ~4 seconds) simply restarts whole PC with no error codes in Event manager. Any though on that? I have 2 certified HDMI 2.1 cables and there is no change in behavior at either 60 or 120 Hz. There are no problems (working from home so using pc for around 12 hours everyday) if I do not change anything (do not change LG C9 settings, do not turn it off, etc.)
2. Anyone knows anything about AMD HDMI 2.1 VRR status at the moment? As far as I know it is not working because in far reaches of the web I did not find anyone who got HDMI 2.1 VRR working (not freesync but HDMI 2.1 VRR). Having LG C9 I can assure you that AMD drivers do not display option to turn on VRR (freesync EDID override does not work because LG C9 does not receive signal after doing it (did the same mod on my 1080 Ti and TV worked 100% just, obviously, did not have freesync).
3. More of a rant really (other RX 6800 (XT) and LG CX or C9 owners input would be appreciated) because official AMD response (to, as far as I'm aware, a known issue) was to try card in a different system – RX 6800 memory speed at 4k 120/100 Hz is at 100% (2000 Mhz) whick not only increases idle power draw from 7-9 W (at 60 Hz) to ~39 W (at 100/120 Hz) but also heats up card quite well.

AMD does not make it easy to like them... Still waiting for a friend to finish Cyberpunk so we can change cards (he has 3080) so I can enjoy metro exodus with ray tracing.
Made an account just to reply to this. I'm experiencing exactly the same issues with a 6900 XT and a LG C9.
I'm speaking to both LG and AMD support and both are playing dumb essentially.
Will keep this updated with any progress.
 

Pabaisa

Weaksauce
Joined
Oct 22, 2013
Messages
81
I'm repeating myself but it fits - AMD does not make it easy to like them - official AMD responses are abysmal, support is non existant, driver tuning section keeps resetting every so often.

Nvidia.... It just works.
 
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