ROG Strix XG27ACG Review
Continuing from my previous post about my journey to find a new monitor, I mentioned that I bought the XG27ACG. I'll do a simple review of it, but do keep in mind that I don't have the technical software or equipment to do the objective reviews that you would see on Rtings or Monitors Unboxed.
My review is given from the perspective of someone who has only used the Dell U2412M, and has never used an OLED monitor before. Because of that, I don't have a good frame of reference or comparison, so keep that in mind when I give my thoughts on the XG27ACG.
First, a quick list of the good and bad points of this monitor.
Good:
Build quality looks solid
No dead or stuck pixels
Picture quality is great
ELMB is effective at reducing motion blur
HDR400 implementation looks good to me
Asus support fixed my issue at no inconvenience to me
Bad:
Poor white/grey uniformity
Poor viewing angles for an IPS
ELMB Sync doesn't do much
ELMB needs to be used with a specific mode to look good
VRR flicker when swapping between apps
The monitor or provided cable is faulty when running high bandwidth content
OSD has bugs where some settings don't revert back to normal after turning it on and off (mainly affecting "Dynamic Dimming", "ASCR", and "sRGB mode")
Asus support is slow as they reply questions at the pace of one a week
Now to go deeper into the above points.
ELMB and ELMB Sync
ELMB is Asus's naming for backlight strobing, where black frames are inserted in between frames to reduce the effect of images persisting in between frames. This aims to reduce motion blur for objects moving on the screen.
I've tested it and it works well, making moving objects clear and sharp. However there is one quirk with it - it causes a strange halo effect around darker objects. This is what I mean:
Thanks to a comment in the video, I've managed to make the halo effect go away when the "FPS mode" is enabled, along with ensuring that the contrast settings on the monitor are set higher than what I usually use.
ELMB Sync is also backlight strobing, but it's ELMB that can be enabled while GSync/FreeSync is enabled. Without ELMB Sync, you have to disable GSync/FreeSync if you want to use it.
ELMB Sync has no halo effects, but I have also not seen any improvements in motion clarity with it enabled. It's as good as useless, if you ask me.
HDR400
HDR400 is a commonly derided standard, as it doesn't offer enough brightness or contrast to be considered proper HDR. Some comments on Reddit would even go so far as to say that HDR400 looks worse than SDR, and that HDR400 shouldn't exist at all.
This isn't my experience at all, and I've found that HDR400 looks amazing. But as mentioned at the start of this review, I've never experienced using an OLED monitor before. I do have an OLED phone and HDR videos also look great on it, but I find that the difference between it and HDR400 is far, far, smaller than the difference between SDR and HDR400.
Poor white/grey uniformity
▲ All white screen with a brightness of 5 and contrast of 15.
▲ All white screen with the "Cinema Mode", which has a brightness of 90 and contrast of 80.
This is my biggest complaint with the monitor, which made me give the monitor 4 out of 5 stars on the website I bought it from.
Coming from the Dell U2412M which has perfect uniformity (at least to my eyes), this monitor is quite a disappointment in this regard. It's the most obvious on bright scenes with a uniform colour, which means that a large part of web browsing and productivity work is affected by this issue.
This issue is improved by having higher brightness and contrast settings, so it's more of a problem for those who prefer darker screens. The images above exaggerate the problem, and I don't have a better camera or the skills to reproduce what the eyes really see.
Fortunately, when looking at entertainment media, this issue isn't visible at all and I have not been affected by this in any way beyond white screens.
Poor viewing angles for an IPS
The uniformity issue mentioned above seems to be made worse by the poor (compared to the U2412M) viewing angles of this monitor. I've noticed that the uniformity issue reduces when looking at the edges of the monitor head on, rather than from the middle.
Standing in front of the monitor and looking down at it also results in a washed out colour, something I've never experienced with the U2412M.
Check out these images, with the following monitor settings:
Brightness: 5
Contrast: 15
Color Space: sRGB
Color Temperature: 7500K
Saturation & Six-axis Saturation: All 50
Gamma: 2.2
▲ Original image
▲ Head on image
▲ Viewed from above
▲ View from the right and left
The horizontal viewing angles aren't bad when it comes to non-white content, so I have no complaints with that. It's only when standing up and looking down at my monitor where it becomes an issue.
VRR Flicker
I'm not sure if what I'm experiencing is indeed VRR flicker, but I've noticed some quick flickers whenever I alt-tab or change between windowed apps with the mouse. I do suspect VRR to be the cause, which is unfortunate as this should be an issue that only affects VA and OLED panels.
On the bright side, I don't see flicker with changing frame rates if I stay within a single application, so maybe this isn't VRR flicker. But the flicker is eliminated entirely when VRR is disabled, so I don't really know.
Provided cable (or monitor) is faulty
This monitor gave me a scare when I first enabled HDR, as doing that would bump the bit depth up to 10-bits. Doing this caused my monitor to black out, occasionally showing an image for a split second.
I didn't want to bother recording a video at first, but since Asus support requested for one, here's a video showing the issue:
And for some reason, Windows 11 does not have the usual revert timer when enabling HDR, so I had to struggle to disable HDR by relying on the short bursts of image visibility.
I've eventually learned about the HDR shortcut (win+alt+B), and I've also figured out why this happens. Basically, it seems that the cable provided seems to top out at about a capable bandwidth of approximately 18 Gbps, while DisplayPort 1.4 is rated to be capable of handing 25.92 Gbps effectively.
Using this handy bandwidth calculator, it's clear that at the base settings of 1440p, 180Hz, and 8-bit, 17.91 Gbps is needed. Using the same settings at 10-bit increases the requirement to 22.28 Gbps.
I've found that the following settings work with my monitor and cable:
10-Bit RGB 120Hz (14.49 Gbps)
10-Bit YUV422 180Hz (11.94 Gbps)
8-Bit RGB 180Hz (17.91 Gbps)
All of these stay well below the 18 Gbps limit, and they all work stably. It's unfortunate that I have to resort to lowering the requirements to be able to run HDR.
Something strange is that 10-Bit RGB 144Hz (17.60 Gbps) doesn't work, so I'm not sure what's going on there.
I am currently in communication with Asus support to see how to get this fixed. They have asked me to try a different cable, but I am somehow very unfortunate with DisplayPort cables as it seems that 4 out of 4 cables all have issues with this monitor. You would think that a sample of 4 out of 4 is quite conclusive that it's not a cable issue, but you'd be surprised. The other three cables, one from Vention (not VESA Certified) and two from Ugreen (VESA Certified) don't even work at 1440p, 180Hz, and 8-bit, which meant that they were both worse than the provided cable, which likely meant that I did manage to get four faulty cables in a row.
How? Well FML I guess.
OSD Bugs
Having on-screen display (OSD) bugs is pretty ironic, considering that I skipped the Xiaomi monitor because I wanted to avoid bugs.
On the first few days after obtaining the monitor, I naturally played around with the settings a lot. I enabled and disabled many settings, and I ended up with settings that don't seem to revert back to normal after turning them on and off.
ASCR and Dynamic Dimming both seem to have something to do with brightness, and turning them on would increase the brightness of the monitor. You would think that turning them off would set the brightness back to normal, but it doesn't. The value of the brightness setting doesn't change either, so it's not possible to lower it back to what it was. The only way was to reset the OSD, which fortunately works to solve the issues.
Turning on and off the sRGB mode of the display also caused issues. Turning on the sRGB mode would fix the brightness of the monitor, and change the color space to sRGB, along with pre-calibrated color settings. If the XG27ACG is similar to the XG27ACS, then this mode provides the best out of the box color accuracy. Turning it off, however, didn't revert the colors back to normal. While the brightness settings do revert back, the colors ended up looking dim and bland, which didn't match the colors before toggling the setting, so I'm not sure what it even reverted to. Fortunately, this issue can also be fixed by resetting the OSD.
On the bright side, the OSD is something you touch only when you get the monitor. Once done and you've settled in, it's not something you use much.
Slow Asus Support
As the HDR doesn't work properly at the maximum support bandwidth settings, I've opened a support case with Asus via email. They take a week to reply a single question, and I'm currently in week 2 of correspondence. So I'm waiting on the answer for my second question.
The person in charge of the support line seems to just be a messenger and while he is responsive, he always replies with "We have forwarded your concern to the relevant department for further checking. Hence, we will revert to you once we have received the feedback."
I'm not sure why Asus has their support system set up this way, but it's pretty bad. The only positive thing that can come out of this is that they provide a good resolution, but that remains to be seen.
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After all these issues, I did come across this rant on Reddit, which I found very relatable: https://reddit.com/r/Monitors/comments/vgvxuu/what_happened_to_ipspanels_these_past_nine_years/
Ironically, it ends up being the Dell Ultrasharp that's able to maintain the best quality again. Maybe I should have gotten the Dell Ultrasharp? But if I did, I would be left regretting and thinking that I should have gotten a gaming monitor with all its extra features. If I had gotten the Xiaomi instead? I would probably be kicking myself with the bugs I encounter, telling myself "I told you so". Hindsight is 20/20. On the bright side, the issues with the XG27ACG aren't a problem 99% of the time, so I'm pretty happy with it.
It seems that the LCD industry kept improving its technology with higher resolutions and refresh rates, but the general picture quality has gone down across the board. Sad, but not unexpected.
Or maybe it's because the industry is focusing on OLED panels nowadays, so they don't really care about LCD. Whatever the cause, it's quite likely that my next monitor will be an OLED, probably 3-5 years down the line. Would I say I'm happy with this monitor? Yeah, probably. It definitely could have been better, and I expected better out of a monitor that's at the top of the price range for a 27 inch, 1440p, IPS. If this costed $100 less, then this be close to perfect, I would say. But again, I don't have a good frame of reference, so I don't really know.
Either way, I'm not sure if I would want to get an Asus for my next monitor. If paying top dollar doesn't get you quality, then why pay for it? I guess it would really depend on how Asus support handles my HDR issue. I'll update the post when the whole thing is resolved (or not resolved).
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Update: my HDR bandwidth issue has been fixed.
Asus support fixed my issue at no inconvenience to me
Despite Asus support being rather slow, they did manage to settle and fix everything without any sort of inconvenience to me. What I mean by this is that this was a free on-site repair, which meant that they sent someone down to my house to check and repair the monitor on the spot.
I didn't have to travel to their support centre, and I didn't have to lose access to my monitor for days or weeks to wait for it to get fixed. It was all complete within an hour.
Pretty impressive, considering the bad reputation Asus got for their warranty earlier this year.
The guy replaced the motherboard in my monitor and everything is working fine now. The monitor's serial number did change though, so I'm not really sure what I'm supposed to do about that. I'll figure it out.
Since the previous motherboard was faulty, it is possible the OSD bugs are fixed, but I didn't bother testing out the OSD again to see if the OSD bugs remained. It could also just be the ports attached to the motherboard that were faulty. I'm not going to debug this, so the case is closed.
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Does this make me feel more positive about getting an Asus monitor in the future? I suppose so. I doubt I would be getting any sort of service at all if I got a Xiaomi, AOC, or KTC monitor. But it would definitely have been better if I didn't have to go through this to begin with. This cost me a $6 new user voucher on Lazada which I used to buy a new cable (and refunded, but the voucher was not returned). It also added a refund on my Shopee account, which probably lowers the amount of refunds I can do in the near future.













