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Re: Asus XG27AQDMG Discussion
Posted: 07 Aug 2024, 12:29
by jorimt
kurtdh wrote: ↑07 Aug 2024, 12:23
"I looked more into it and NVIDIA says this: "NVIDIA DSR, NVIDIA DLDSR and NVIDIA Image Scaling are supported when DSC mode is enabled, if the pixel rate needed to drive the display mode does not exceed the GPU's single head limit. If GPU uses two or more internal heads to drive the display, NVIDIA DSR, NVIDIA DLDSR and NVIDIA Image Scaling are not supported."
That would explain why I can't use them on my PG27AQN when DSC is enabled then; I believe it uses two heads.
Re: Asus XG27AQDMG Discussion
Posted: 07 Aug 2024, 12:46
by Chief Blur Buster
RealNC wrote: ↑04 Aug 2024, 18:00
Not sure why I didn't try this at first, but it's simply the vertical total that matters. Nothing else. Lower VT by 5 in "manual" settings mode, until it stops flickering in VRR.
That's about it, it seems
The Guru3D guide is the best one so far.
This tweak sometimes works but it is very display-specific.
If someone says it works on display X, then definitely worth trying!
Also, make sure it's not an accidental LFC-defeat or LFC-force hack (domino effect of modifying LFC settings indirectly accidentally via Vertical Total changes). Or that the change to VT changes the overdrive algorithm, creating slightly more ghosting at certain frame rates but fixing the VRR flicker. Or some other unexpected tradeoff was made. Sometimes there's no tradeoff visible and the manufacturer messed up.
Experimentaiton is key, much like editing VRR ranges. You may find that tweaks like this may help X% (e.g. 10%) of panels, for example. The fix is likely not very universal, except on specific panels.
Give it a try!
Re: Asus XG27AQDMG Discussion
Posted: 07 Aug 2024, 13:38
by RealNC
Chief Blur Buster wrote: ↑07 Aug 2024, 12:46
The Guru3D guide is the best one so far.
This tweak sometimes works but it is very display-specific.
If someone says it works on display X, then definitely worth trying!
Also, make sure it's not an accidental LFC-defeat or LFC-force hack (domino effect of modifying LFC settings indirectly accidentally via Vertical Total changes). Or that the change to VT changes the overdrive algorithm, creating slightly more ghosting at certain frame rates but fixing the VRR flicker. Or some other unexpected tradeoff was made. Sometimes there's no tradeoff visible and the manufacturer messed up.
Experimentaiton is key, much like editing VRR ranges. You may find that tweaks like this may help X% (e.g. 10%) of panels, for example. The fix is likely not very universal, except on specific panels.
Give it a try!
(This is an OLED, so I don't think there's overdrive.)
After a couple days of testing, I think I found the horrible truth when testing a 2D side scrolling game where frame skips are easy to detect: the tweak doesn't actually work. I'll paste my Guru3D post here:
Some research brought up that OLED displays define their gamma response based on the maximum refresh rate. So this is what causes the flicker. And indeed, at least here, if I define two FPS caps (one with RTSS at 60FPS and one with NVCP at 150FPS,) then switch between the two in-game by toggling the RTSS cap on/off in some area with dark colors and shadows, the gamma changes and shadows appear brighter. And they stay brighter until I switch back to the 120FPS cap.
So it seems the flicker has nothing to do with "exceeding limits" or anything like that. The CRU tweak appears to simply prevent g-sync from syncing correctly. OLEDs simply have a different gamma curve at different refresh rates. And if your FPS fluctuates, the gamma curve will fluctuate in response, which is what this "flicker" is about.
This tweak appears to be a "too good to be true" thing. It basically has the same result as disabling VRR :-/ The only difference is that everything else around VRR continues to work. The monitor OSD Hz indicator shows current VRR rate, the hardware mouse cursor being updated at whatever the current Hz is rather than max Hz, the g-sync indicator when enabled in NVCP being displayed... But the actual sync doesn't appear to be happening.
Re: Asus XG27AQDMG Discussion
Posted: 07 Aug 2024, 16:23
by jorimt
RealNC wrote: ↑07 Aug 2024, 13:38
After a couple days of testing, I think I found the horrible truth when testing a 2D side scrolling game where frame skips are easy to detect: the tweak doesn't actually work.
Unfortunate.
As I suggested in the AVS forums
(and probably here) years ago, if the VRR flicker is indeed due to a fixed gamma curve at the max refresh rate, we'd need a hypothetical gamma LUT instead of GtG LUT like we have with native G-SYNC LCD displays
(aka variable overdrive), which I doubt any of the display manufacturers are working on, let alone considering, especially seeing as their latest "solution" was to essentially shrink the working VRR range on OLED.
My guess is there are micro gamma shifts on LCDs during VRR operation as well, but they simply aren't detectable due to that panel type being unable to reach true black. I.E. OLED is likely revealing a weakness of VRR operation that was always there, but is just now visible on that panel type.
Re: Asus XG27AQDMG Discussion
Posted: 07 Aug 2024, 23:28
by kurtdh
jorimt wrote: ↑07 Aug 2024, 16:23
RealNC wrote: ↑07 Aug 2024, 13:38
After a couple days of testing, I think I found the horrible truth when testing a 2D side scrolling game where frame skips are easy to detect: the tweak doesn't actually work.
Unfortunate.
As I suggested in the AVS forums
(and probably here) years ago, if the VRR flicker is indeed due to a fixed gamma curve at the max refresh rate, we'd need a hypothetical gamma LUT instead of GtG LUT like we have with native G-SYNC LCD displays
(aka variable overdrive), which I doubt any of the display manufacturers are working on, let alone considering, especially seeing as their latest "solution" was to essentially shrink the working VRR range on OLED.
My guess is there are micro gamma shifts on LCDs during VRR operation as well, but they simply aren't detectable due to that panel type being unable to reach true black. I.E. OLED is likely revealing a weakness of VRR operation that was always there, but is just now visible on that panel type.
The end game monitor remains elusive. I thought the FO32U2P was it for me, but the VRR flicker is aggravating. I'm putting up with it because it seems to plague all OLED monitors, but I'm hoping VRR flicker stops being a thing in the next couple of years and I can upgrade again to my "end game" monitor.
Re: Asus XG27AQDMG Discussion
Posted: 08 Aug 2024, 02:23
by RealNC
jorimt wrote: ↑07 Aug 2024, 16:23
RealNC wrote: ↑07 Aug 2024, 13:38
After a couple days of testing, I think I found the horrible truth when testing a 2D side scrolling game where frame skips are easy to detect: the tweak doesn't actually work.
Unfortunate.
Unless it actually somehow works, except for me
Have you tried this out? Either VT tweak or -10Hz tweak.
Re: Asus XG27AQDMG Discussion
Posted: 08 Aug 2024, 03:48
by gunner7
I’ve been eyeing this monitor and have been following RealNC’s findings over the last few days. Is it still the case that there is no VRR flicker in 180hz mode? Hoping yes, but not getting my hopes up.
Re: Asus XG27AQDMG Discussion
Posted: 08 Aug 2024, 04:01
by RealNC
gunner7 wrote: ↑08 Aug 2024, 03:48
I’ve been eyeing this monitor and have been following RealNC’s findings over the last few days. Is it still the case that there is no VRR flicker in 180hz mode? Hoping yes, but not getting my hopes up.
There isn't, but it turns out there's judder (very easy to pick up in 60FPS side scrollers, I was only testing 90 to 120FPS before.) So I now believe the only reason there's no flicker is simply because VRR doesn't work correctly in the default 180Hz mode, or when using the tweaked versions of the other modes.
Re: Asus XG27AQDMG Discussion
Posted: 08 Aug 2024, 04:22
by gunner7
I was really hoping I could use this monitor for 240hz competite and 180hz single player games with VRR. If the judder is practically unnoticeable in 180hz default mode, I hope some more testing is done whether or not VRR is actually working as advertised. Could be a trade off I could accept if so.
Re: Asus XG27AQDMG Discussion
Posted: 08 Aug 2024, 04:37
by RealNC
gunner7 wrote: ↑08 Aug 2024, 04:22
I was really hoping I could use this monitor for 240hz competite and 180hz single player games with VRR. If the judder is practically unnoticeable in 180hz default mode
It looks about the same as the tweaked 240Hz mode. Even slightly worse, I'd say. (The higher the Hz, the less noticeable judder becomes. Which is what threw me off at first. 240Hz judder is harder to see compared to the 144Hz that I was using with my previous monitor.)