Asus XG27AQDMG Discussion

[RealNC]

The 180Hz mode of this monitor is broken when g-sync is enabled in the nvidia control panel in all currently available firmware versions. See "Update 2" near the bottom of this post. 240Hz, 144Hz, 120Hz and 60Hz are perfectly fine.

Banding/posterization issues: 6-bit temporal dithering helps a lot. See "Update 4" below.

12-bit color support can be added. See "Update 5" below.

The Asus XG27AQDMG just arrived. Very first impressions compared to my previous displays (ViewSonic XG2703-GS and XG270QG, both IPS):

• Screen is not full glossy. I'd say it's about 80% glossy. So there is at least some diffusion happening. Which is perfectly fine with me. The XG2703-GS was more like 50/50 (and my crappy TN 100% full matte.) The image quality is very clear, as you would expect from a glossy panel.
• Black stays black even with fully lit room during the day.
• There is no ghosting or overshoot whatsoever. Like, none at all. And I think this just goes to show how good these ViewSonic IPS monitors were at this, because the difference to OLED is not as big as I imagined.
• The wide gamut is wider than the XG270QG. The sRGB clamp works, but it breaks black levels. In the Lagom black level test, I can see a difference between all squares in full gamut, but in sRGB mode the first four squares are indistinguishable. Using the novideo_srgb tool for the sRGB clamp instead works perfectly fine with only minimal black crush.
• Text fringing only exists in Windows. On Linux, text looks great, just like on the previous IPS screens. Microsoft appears to not care about fixing ClearType for the various OLED subpixel layouts? Anyway, it's not an actual issue, unless I keep pixel peeping the text.
• I need to close the window curtains behind me to avoid reflections But once I do that, it's perfect.
• Brightness is great. The monitor is too bright for me already at 50% brightness. I use 35% right now (day. 2pm.) If I open the window curtains, I set it to 45% brightness. This is all with the "uniform brightness" setting enabled (so ABL is disabled,) and with the "Screensaver" option disabled (enabling it just dims the screen, no idea why use that instead of just lowering brightness instead.) 100% brightness is way, way too bright for me. So I'm happy that OLED brightness turns out to not be an issue for me whatsoever.
• Contrast stays great even when I darken the room. Yey OLED! IPS always needed at least some bias lighting (I have it installed behind my desk) to maintain good contrast.
• Colors are good. Not a huge difference to the IPS panels, but still a noticeable improvement.
• Gamma is off. The default setting is 2.2, but this results in ~2.3. I need to set it to 2.0 to get ~2.15 at 240Hz. At 120Hz gamma changes and it needs to be set to 2.2. Basically the lower the refresh rate gets, the lower the gamma gets too. This appears to be a common OLED thing.
• 240Hz on the desktop makes no difference to me compared to 120Hz. By that I mean I can clearly see and feel the difference, it's just that 120Hz is already "good enough" for me. 240Hz in games though is great to have, even when capping to 120FPS, just for the extra latency benefit.
• Screen uniformity is way better than the IPS displays I had. Except gray, which shows the typical W-OLED stripes I've seen in reviews. But it's fine, it only is visible in full screen full gray, and even then it's not anything severe.
• Viewing angles: 100% perfect from any angle. If you thought IPS is already good at this (which it is,) try OLED It feels weird to not see the IPS glow anymore when looking to the bottom of the screen at an angle...
• Build quality seems OK-ish. It's sturdy, but no comparison to the premium build and feel of the ViewSonic XG270QG with it's use of metal and the best monitor stand I've ever seen in my life. The Asus is just plastic. But it's not flimsy, so it's not terrible. Just OK-ish. And the height adjustment is a bit limited. At full height, the very top of the display is barely at eye height. I should probably get something to put under the monitor to get some more height. (Keep in mind though that I'm 1.96m/6'5".) But I must say, for 800€, I expected a bit better that what Asus is delivering here when it comes to height adjustment. Although on the other hand, since there's no IPS glow anymore, I might just get used to the monitor not being higher than eye height.

Haven't done any gaming yet nor tried any BFI. Will do this evening. Right now, I'm happy, especially about the great text clarity on Linux. This was one of my biggest worries.

(Update: BFI works fine, but it increases latency by a lot. See the RTINGS review to see the latency results. I don't use BFI anway, so I don't really care.)

Huge relief: RGB and power LED can be disabled in the OSD without having to install some Asus RGB crapware

Firmware Update

A caveat for Linux and macOS users: The firmware update over a USB stick does NOT work. The documentation says to format as FAT32 and copy the firmware file into it, then press the menu button for 5 seconds, but as soon as the firmware update message appears, the monitor shuts down and does not update the firmware.

I had to boot to Windows and download the Windows firmware update tool instead.

sRGB Mode Black Crush

The monitor's sRGB mode has some black crush (quite a bit, I'd say.) It's fixable by leaving the monitor in wide gamut mode and using novideo_srgb instead to do the sRGB clamp. Unfortunately, this only works with Nvidia GPUs:

novideo_srgb.png (22.89 KiB) Viewed 43343 times

(6-bit dither helps with banding. See "update 4" below.)

"OK" and then simply enable the "clamp" checkbox. You don't need to activate "run at startup". The clamp will persist across reboots. You probably will need to reapply it after driver upgrades, and also you probably have to manually disable it if you want to enable HDR. With this, the black level test on lagom should give better results compared to the monitor's built-in sRGB mode, with more squares being visible:

http://www.lagom.nl/lcd-test/black.php

Note that this doesn't actually load the ICC profile or anything. The color corrections are performed by the GPU and affect everything. The desktop, games and all applications.


Update 1
RTINGS video is up:

phpBB [video]

Update 2
The 180Hz mode of this monitor is broken when g-sync is enabled. VRR isn't actually working correctly even though all indicators say it does, and some frames appear to be staying on the screen longer than others. VRR doesn't actually have to be currently active. It happens even on the desktop or when selecting "fixed refresh" in the nvidia panel. Moving the mouse quickly to get a stroboscopic effect on the mouse cursor results in this:

xg27aqdmg_180hz.png (1.81 KiB) Viewed 54076 times

Every third frame, you get a brighter cursor, suggesting the frame is visible for longer, or the other frames are visible for shorter. Is if 180Hz is a mish-mash of 240Hz and 60Hz. I don't know for sure.

Disabling g-sync in the nvidia panel fixes it. Contacting Asus support is not useful ("update your drivers, turn it off and on again, etc, etc, etc." It's a bug in the monitor and needs to be fixed in a firmware update, but Asus apparently has zero interest.)


Update 3
The firmware bug where the monitor will sometimes fail to apply image and color settings when waking up from standby mode has been fixed in firmware MCM104.


Update 4
Darker color shades can exhibit banding/posterization. The lower the refresh rate (including low FPS VRR at 240Hz), the more visible the issue becomes. Using 6-bit temporal dithering helps quite a bit. This includes 10-bit HDR mode. You can use novideo_srgb to set 6-bit temporal dither in the "advanced" settings of novideo_srgb. You can also set it in Special K, if you use that (and it's a permanent global setting that applies to everything, just like with novideo_srgb.)

Do not enable the sRGB color clamp checkbox in novideo_srgb for HDR! Only enable dithering.

This HDR gradient test improves by a lot with 6-bit temporal dither: https://www.youtube.com/watch?v=PoMPrr-Uefs


Update 5
Like most W-OLED displays, the monitor supports 12-bit color, not just 10-bit. It needs to be added with ToastyX CRU. I do not know whether or not it has any benefits compared to 10-bit.

With DSC turned off, 144Hz is the highest refresh rate where you can enable 12-bit colors.

cru_12bpp.png (14.76 KiB) Viewed 41808 times

nvcp_12bpp.png (15.89 KiB) Viewed 41808 times

osd_12bpp.jpg (166.55 KiB) Viewed 41808 times

[jorimt]

Nice, will be interesting to hear your thoughts on its VRR performance once you've had some time with it.

[RealNC]

Nice, will be interesting to hear your thoughts on its VRR performance once you've had some time with it.

Tested a couple games now for a few minutes each (from Forza to Doom to Halo 2 to Witcher 3.) Seems very solid. I think I can detect some increased input lag when running 60FPS@120Hz g-sync vs 60FPS@240Hz g-sync though. Mouse look seems a tiny bit more floaty.

VRR flicker is there. Not only on loading screens. I spotted flicker in Halo 2 with in-game 60FPS cap. Using NVCP or RTSS cap instead fixes it.

240FPS@240Hz looks nice, but I wouldn't call it transformative. 120FPS already looks excellent to me (in fact even 90FPS look really good here,) but of course that's just personal preference. Not sure if placebo, but 90FPS on the OLED looks more like 100FPS on the IPS screens, or 120FPS on the TN (which has broken overdrive in VRR.) What's more transformative is the perfect darkness when running these very dark Halo 2 corridors with the contrasting LED lights on the walls. This actually looks superb.

And 60FPS isn't that bad now either. It's still "framey," and has of course motion blur, but a bit less so than the IPS screens.

BFI does what it says on the box. But it only works at 120Hz. There's no 100Hz or 85Hz modes at all. I added them with CRU, but BFI can't be used. I also tried to match pixel clock with the 120Hz mode by changing VT in 100Hz, but it still doesn't work and on top of that the display glitches out (random parts of the image move around in a flickery fashion.) Maybe we can petition Asus to add 100/85/60Hz BFI?

Motion blur with BFI ("ELMB" in this case ) at 120FPS/120Hz matches what you see at 240FPS/240Hz without BFI, which is to be expected. It's just BFI so impossible to change pulse width like you can with a backlight. On the plus side, there's no flicker at all, and the brightness is still plenty (100% brightness with BFI is still too much for me, I set it to 85%, though this is also a personal preference thing.) HDR doesn't work with BFI and neither does VRR.

I noticed that DSC can be turned off in the OSD. This limits 10-bit to a max of 180Hz. For 240Hz only 8-bit is allowed. So apparently the only reason to keep DSC enabled with this monitor is for just one mode: 10-bit 240Hz 1440p.

One thing I don't like is that the OSD doesn't tell you which refresh rate mode it's using. If I run 240Hz or 144Hz or whatever, it only shows the current VRR refresh rate, so I have no idea if I'm using max Hz mode or not. Also, the OSD has quite a few useless Asus nonsense that nobody needs. RPG mode, Racing mode, MOBA mode, Night Vision mode... Using "MOBA mode" for example just turns everything green. What's the point? None whatsoever. It only clutters the OSD needlessly. Instead of that, I would rather want the OSD to tell me the maximum Hz of the current video mode.

Anyway, I think this will be a keeper unless something ugly rears its head during the next few days.

[jorimt]

VRR flicker is there. Not only on loading screens. I spotted flicker in Halo 2 with in-game 60FPS cap. Using NVCP or RTSS cap instead fixes it.

Yup.

Not sure if placebo, but 90FPS on the OLED looks more like 100FPS on the IPS screens, or 120FPS on the TN (which has broken overdrive in VRR.)

Not necessarily placebo; OLED's near instantaneous pixel response can give the impression of a slightly higher effective refresh rate at the same refresh rate of otherwise equivalent LCDs.

I noticed that DSC can be turned off in the OSD. This limits 10-bit to a max of 180Hz. For 240Hz only 8-bit is allowed. So apparently the only reason to keep DSC enabled with this monitor is for just one mode: 10-bit 240Hz 1440p.

8-bit dithered vs native 10-bit isn't very noticeable in 99% of cases, at least in my experience. DSC is better off, where possible (less glitches, DLDSR and custom resolution support, etc).

One thing I don't like is that the OSD doesn't tell you which refresh rate mode it's using. If I run 240Hz or 144Hz or whatever, it only shows the current VRR refresh rate, so I have no idea if I'm using max Hz mode or not.

Do you not have this readout? Pulled it from your monitor manual.

refresh-rate-readout.png (64.1 KiB) Viewed 60773 times

That should give you your currently set physical refresh rate, or does it change with VRR? Mine doesn't; it has a separate readout for VRR.

[RealNC]

Do you not have this readout? Pulled it from your monitor manual.

That should give you your currently set physical refresh rate, or does it change with VRR? Mine doesn't; it has a separate readout for VRR.

Nope, this monitor doesn't have a separate readout. It changes and only shows current VRR refresh rate. And very badly too, since it jumps a lot even with perfectly capped frame pacing.

There is an "Information" section in the OSD that lists all sorts of things, like color depth (8-bit or 10-bit,) color format (like RGB 444,) color range (full or limited,) etc, but they didn't include the current refresh rate, lol.

[jorimt]

Nope, this monitor doesn't have a separate readout. It changes and only shows current VRR refresh rate.

Lame.

And very badly too, since it jumps a lot even with perfectly capped frame pacing.

Par for the course with these, unfortunately.

Don't know if you already have it, but this unofficial RTSS add-on shows the current VRR status more accurately than the monitor, and even reflects the LFC multiple:
https://www.forum-3dcenter.org/vbulleti ... st11931346

I've used it recently, and it still seems to work with newer versions of RTSS.

[RealNC]

(Split to a new topic.)

Don't know if you already have it, but this unofficial RTSS add-on shows the current VRR status more accurately than the monitor, and even reflects the LFC multiple:
https://www.forum-3dcenter.org/vbulleti ... st11931346

I've used it recently, and it still seems to work with newer versions of RTSS.

I think RTSS has that directly built-in now. It just needs to be added in the overlay editor. Will check later to make sure.

[jorimt]

I think RTSS has that directly built-in now. It just needs to be added in the overlay editor. Will check later to make sure.

Even better, if so.

[kyube]

The Asus XG27AQDMG just arrived. Very first impressions compared to my previous displays (ViewSonic XG2703-GS and XG270QG, both IPS):

[*]Text fringing only exists in Windows. On Linux, text looks great, just like on the previous IPS screens. Microsoft appears to not care about fixing ClearType for the various OLED subpixel layouts?
...

Did you do anything in particular to make it render akin to LCD? Could you take any comparison shots?

...
[*]240Hz on the desktop makes no difference to me compared to 120Hz.
...

This sounds extremely odd to me.
A 2x jump in refresh rate, especially with low g2g's like on OLED should feel substantially better.
I assume since you're on Linux, it's masking the latency benefits.
+ w/ the games you've mentioned you play, I assume your 0.1% lows are all over the place, hence you don't notice it as much.

[RealNC]

Did you do anything in particular to make it render akin to LCD? Could you take any comparison shots?

I had freetype configured to only do slight font hinting. As a result, it's mostly grayscale anti-aliasing. So fringing is pretty much non-existent.

Not sure how to do this on Windows. Last time I tried grayscale font anti-aliasing on Windows, text looked like dogshit

...
[*]240Hz on the desktop makes no difference to me compared to 120Hz.
...

This sounds extremely odd to me.
A 2x jump in refresh rate, especially with low g2g's like on OLED should feel substantially better.
I assume since you're on Linux, it's masking the latency benefits.
+ w/ the games you've mentioned you play, I assume your 0.1% lows are all over the place, hence you don't notice it as much.

Oh, the difference is obvious. Way smoother and clearer when moving a window around or when scrolling in Firefox. It just doesn't make a difference to me. I meant that 120Hz is already good enough for me on the desktop. The extra smoothness and clarity of 240Hz just doesn't matter much to me.

In games it seems more useful, but still, 120 is again good enough for me. Again, the difference in clarity and smoothness is clear as day, but it just turns out this isn't important to me.

Edit:
I'd also like to avoid the case where I get so used to 240FPS@240Hz that 120 then starts to look like crap to me. It's gonna come and bite me in the ass later on if that happens (It happened already with 60 vs 120...)