2020 QLED T models (Q80T, Q90T, Q800T, Q900T) HDR game mode brightness / local dimming bug

[Rauttis]

I bought a Q80T a couple of days ago and have noticed a really annoying issue when using the tv with the combination of HDR and game mode.

I'm fairly certain this is a software bug in the TV since I can reproduce this issue with 100% accuracy, and it happens on the dot at the same moment every time. It's basically on a timer.

Basically when the game is displaying a HDR signal and game mode is enabled, exactly after 6 minutes the brightness of the TV suddenly drops by around 20 (50 -> 30). The value of brightness setting doesn't actually change however. Messing with the brightness setting does not restore the brightness to it's original state, but changing the local dimming setting from standard to low and then back to standard does. Switching game mode off and then back on also fixes the issue, but then it happens again EXACTLY after 6 minutes (I've timed this with a stopwatch).

Has anyone else experienced this issue? Or can someone maybe test this on their TV to see if you can reproduce it?

Exact repro steps on how I can reproduce this 100% of the time on the PS4 Pro:

1. Set brightness to max (50)
2. Set local dimming to standard (bug happens on high as well)
3. Enable game mode
4. Turn off game motion plus
5. Turn off intelligent mode and all the brightness related settings in eco settings, as these can influence the brightness level of the tv.
6. Launch a game that runs in HDR
7. Start your stopwatch
8. Do whatever you want in the game or you can also go back to PS4 menus, find a bright scene where you can notice a brightness drop easily
9. When the stopwatch hits 6 minutes, you should see the TVs brightness suddenly drop by a large amount. By eye the brightness drop seems about equal to dropping the brightness from 50 -> 30 by hand.
10. Go to picture settings and set local dimming to low (brightness does not change)
11. Set local dimming back to standard (brightness suddenly jumps to the original level. Brightness can be restored by switching input away and back as well, or by disabling and re-enabling game mode)
12. And again after EXACTLY 6 minutes the bug again repeats and the brightness drops down again

Some other notes: The PS4 has a screensaver that basically dims the screen if it is idle for a while. This is not the cause of this, this happens even when the console is in active use and the brightness can be restored temporarily by changing the local dimming setting like described above. I have not managed to reproduce this issue with game mode off, so it seems to be related to game mode.

Software version: 1304

[DUSKTILLDAWN]

Freesync auto turns off GMP you can't have both on ,but in other section people are saying GMP won't run at 120hz so yes freesync is issue and turning freesync or GMP off is issues so yes next gen with q90t will probably be broke unless the hdmi cable with more bandwidth changes these issues .

[RouDeR]

It is not a "bandwidth" issue,
It is technology limitation, 
You can't have Freesync (VRR) + GMP (Motion enterpolation) at the same time

Also GMP is OFF in 120hz because it works only up to 60hz as it simulates double FrameRate, and since the panel is 120hz, you can't simulate 240hz , therefore it is OFF.

[lmpcardoso]

Are you sure the VRR does not work with GMP ON?

I have the problem on Q80T with the inverted colors with GMP OFF, if that is true, I'm done with this TV.

Anyway I think I'm already tired of this TV since the beginning.

[DUSKTILLDAWN]

didn't say it's bandwidth I meant unless plugging in 2.1 changes the issues I have while viewing ,some one asked about GMP and freesync which can't be on at same time ,on my UK q90t freesync is dark like horrible dark, freesync off GMP on slider 1 notch colour returns better,GMP off and scrolling faint lines on Xbox dash if you stare you see them but not obvious while gaming,my family is qled nuts we have a q7fn which also was updated and has scrolling lines ,a q60r,q70t,q9fn,and I have UK 55 Q90T ,so if GMP is unavailable at 120 Hz then my series X will have have an issue unless hdmi 2.1 cable and device makes a difference.

[jayh89]

Sounds like someone needs to make a thread about this VRR being very dark issue to bring it to Samsung's attention before next gen in 5 weeks!!

[DUSKTILLDAWN]

Yes vrr does not not work with GMP on ,I have GMP on with slider on 1 because GMP off for me gives faint scrolling lines on Xbox dash ,and if GMP does not work at 120hz,I'm stuffed because my only option then is freesync which Is like gaming in movie mode ,too dark colours off ,contrast is wrong ,

Hgig is then messed up aswell due to this,unless like I said earlier a true hdmi 2.1 device and cable makes a difference to my issues if not then I'll sell it.

[DUSKTILLDAWN]

HDR freesync has been dark on previous year models ,but the difference on this year they auto implement freesync ,only way to turn it off is vrr tab in display settings on Xbox,last year's you could leave vrr tab ticked but freesync was on the TV settings basic or ultimate,this is an ongoing issue made worse by comparing edge lit freesync against full array freesync with same issue,and has always had issues in pic quality compared to people running with GMP on or off,at moment I see 1402.1 and 1406.2,and 1402.7 posted on here different regions and different models Q80T, q90t,q95t,and some on PS4 some on Xbox, I think this will be a worse issue when 120hz consoles but I'm not God so I can't test 2.1 early.

[CypherXCII]

Uuh, I'm playing on an Xbox one x with freesync on and I have no problems with dark images with freesync. it looks very nice and with the HGIG option even better than before. Can you maybe upload some pictures? This is my setting with freesync enabled. as you can see i can still increase the brightness. Im from the Netherlands btw.

 

 

 

[DUSKTILLDAWN]

Yes I'll post some when I can get home ,are you UK based q80t ,90t,95t,which firmware are you on ,do you seegsee a much brighter  less dirty dark with freesync turned off,also with freesync off and GMP off looking at Xbox setting do you see faint scrolling vertical lines going up screen,I'm on uk 55 Q90T,don't see these issues on q60r in other room on q60r edge lit from last year freesync and non freesync are very similar on my Q90T no way

, freesync HDR I'm using warzone set at 4k 60 on Xbox,

[CypherXCII]

I've a q95t 65" from the Netherlands with firmware 1402.6

I dont have faint scrolling lines in the Xbox menu with both disabled (freesync and gmp). Here are two pictures with freesync on and off.