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A Look into Reported G-Sync Display Flickering

Manufacturer: PC Percpective

Overview

We’ve been tracking NVIDIA’s G-Sync for quite a while now. The comments section on Ryan’s initial article erupted with questions, and many of those were answered in a follow-on interview with NVIDIA’s Tom Petersen. The idea was radical – do away with the traditional fixed refresh rate and only send a new frame to the display when it has just completed rendering by the GPU. There are many benefits here, but the short version is that you get the low-latency benefit of V-SYNC OFF gaming combined with the image quality (lack of tearing) that you would see if V-SYNC was ON. Despite the many benefits, there are some potential disadvantages that come from attempting to drive an LCD panel at varying periods of time, as opposed to the fixed intervals that have been the norm for over a decade.

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As the first round of samples came to us for review, the current leader appeared to be the ASUS ROG Swift. A G-Sync 144 Hz display at 1440P was sure to appeal to gamers who wanted faster response than the 4K 60 Hz G-Sync alternative was capable of. Due to what seemed to be large consumer demand, it has taken some time to get these panels into the hands of consumers. As our Storage Editor, I decided it was time to upgrade my home system, placed a pre-order, and waited with anticipation of finally being able to shift from my trusty Dell 3007WFP-HC to a large panel that can handle >2x the FPS.

Fast forward to last week. My pair of ROG Swifts arrived, and some other folks I knew had also received theirs. Before I could set mine up and get some quality gaming time in, my bro FifthDread and his wife both noted a very obvious flicker on their Swifts within the first few minutes of hooking them up. They reported the flicker during game loading screens and mid-game during background content loading occurring in some RTS titles. Prior to hearing from them, the most I had seen were some conflicting and contradictory reports on various forums (not limed to the Swift, though that is the earliest panel and would therefore see the majority of early reports), but now we had something more solid to go on. That night I fired up my own Swift and immediately got to doing what I do best – trying to break things. We have reproduced the issue and intend to demonstrate it in a measurable way, mostly to put some actual data out there to go along with those trying to describe something that is borderline perceptible for mere fractions of a second.

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First a bit of misnomer correction / foundation laying:

  • The ‘Screen refresh rate’ option you see in Windows Display Properties is actually a carryover from the CRT days. In terms of an LCD, it is the maximum rate at which a frame is output to the display. It is not representative of the frequency at which the LCD panel itself is refreshed by the display logic.
  • LCD panel pixels are periodically updated by a scan, typically from top to bottom. Newer / higher quality panels repeat this process at a rate higher than 60 Hz in order to reduce the ‘rolling shutter’ effect seen when panning scenes or windows across the screen.
  • In order to engineer faster responding pixels, manufacturers must deal with the side effect of faster pixel decay between refreshes. This is a balanced by increasing the frequency of scanning out to the panel.
  • The effect we are going to cover here has nothing to do with motion blur, LightBoost, backlight PWM, LightBoost combined with G-Sync (not currently a thing, even though Blur Busters has theorized on how it could work, their method would not work with how G-Sync is actually implemented today).

With all of that out of the way, let’s tackle what folks out there may be seeing on their own variable refresh rate displays. Based on our testing so far, the flicker only presented at times when a game enters a 'stalled' state. These are periods where you would see a split-second freeze in the action, like during a background level load during game play in some titles. It also appears during some game level load screens, but as those are normally static scenes, they would have gone unnoticed on fixed refresh rate panels. Since we were absolutely able to see that something was happening, we wanted to be able to catch it in the act and measure it, so we rooted around the lab and put together some gear to do so. It’s not a perfect solution by any means, but we only needed to observe differences between the smooth gaming and the ‘stalled state’ where the flicker was readily observable. Once the solder dust settled, we fired up a game that we knew could instantaneously swing from a high FPS (144) to a stalled state (0 FPS) and back again. As it turns out, EVE Online does this exact thing while taking an in-game screen shot, so we used that for our initial testing. Here’s what the brightness of a small segment of the ROG Swift does during this very event:

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Measured panel section brightness over time during a 'stall' event. Click to enlarge.

The relatively small ripple to the left and right of center demonstrate the panel output at just under 144 FPS. Panel redraw is in sync with the frames coming from the GPU at this rate. The center section, however, represents what takes place when the input from the GPU suddenly drops to zero. In the above case, the game briefly stalled, then resumed a few frames at 144, then stalled again for a much longer period of time. Completely stopping the panel refresh would result in all TN pixels bleeding towards white, so G-Sync has a built-in failsafe to prevent this by forcing a redraw every ~33 msec. What you are seeing are the pixels intermittently bleeding towards white and periodically being pulled back down to the appropriate brightness by a scan. The low latency panel used in the ROG Swift does this all of the time, but it is less noticeable at 144, as you can see on the left and right edges of the graph. An additional thing that’s happening here is an apparent rise in average brightness during the event. We are still researching the cause of this on our end, but this brightness increase certainly helps to draw attention to the flicker event, making it even more perceptible to those who might have not otherwise noticed it.

Some of you might be wondering why this same effect is not seen when a game drops to 30 FPS (or even lower) during the course of normal game play. While the original G-Sync upgrade kit implementation simply waited until 33 msec had passed until forcing an additional redraw, this introduced judder from 25-30 FPS. Based on our observations and testing, it appears that NVIDIA has corrected this in the retail G-Sync panels with an algorithm that intelligently re-scans at even multiples of the input frame rate in order to keep the redraw rate relatively high, and therefore keeping flicker imperceptible – even at very low continuous frame rates.

A few final points before we go:

  • This is not limited to the ROG Swift. All variable refresh panels we have tested (including 4K) see this effect to a more or less degree than reported here. Again, this only occurs when games instantaneously drop to 0 FPS, and not when those games dip into low frame rates in a continuous fashion.
  • The effect is less perceptible (both visually and with recorded data) at lower maximum refresh rate settings.
  • The effect is not present at fixed refresh rates (G-Sync disabled or with non G-Sync panels).

This post was primarily meant as a status update and to serve as something for G-Sync users to point to when attempting to explain the flicker they are perceiving. We will continue researching, collecting data, and coordinating with NVIDIA on this issue, and will report back once we have more to discuss.

During the research and drafting of this piece, we reached out to and worked with NVIDIA to discuss this issue. Here is their statement:

"All LCD pixel values relax after refreshing. As a result, the brightness value that is set during the LCD’s scanline update slowly relaxes until the next refresh.

This means all LCDs have some slight variation in brightness. In this case, lower frequency refreshes will appear slightly brighter than high frequency refreshes by 1 – 2%.

When games are running normally (i.e., not waiting at a load screen, nor a screen capture) - users will never see this slight variation in brightness value. In the rare cases where frame rates can plummet to very low levels, there is a very slight brightness variation (barely perceptible to the human eye), which disappears when normal operation resumes."

So there you have it. It's basically down to the physics of how an LCD panel works at varying refresh rates. While I agree that it is a rare occurrence, there are some games that present this scenario more frequently (and noticeably) than others. If you've noticed this effect in some games more than others, let us know in the comments section below. 

(Editor's Note: We are continuing to work with NVIDIA on this issue and hope to find a way to alleviate the flickering with either a hardware or software change in the future.)


December 2, 2014 | 03:34 PM - Posted by Zushiba (not verified)

I've got an Acer XB270H, it was supposed to be the Acer XB280HK, but nVidia shipped winners of their #Game24 the wrong monitor.

Still it's G-Sync @ 144Hz, I've noticed flicker on any still image like loading screens. It's especially evident in Dragon Age Inquisition or WoW during a static loading screens. Not something I would consider a deal breaker when looking at a G-Sync display. During game-play it's beautiful, and really that's what matters and the flicker itself is hardly noticeable.

There's no flicker during desktop use or image editing.

December 2, 2014 | 03:45 PM - Posted by Gumby

Zushiba I was wondering if you ever got that monitor, good to see it did arrive. kittenswin

December 2, 2014 | 03:42 PM - Posted by Mountainlifter

While this might not be relevant to Gsync itself, the ROG swift has been having other problems. I wrote a little guide (work in progress) for the issues others and I are facing.

Could these issues be related as in could the issues I listed out be a result of the way gsync works?

http://www.overclock.net/t/1526956/guide-to-the-problems-with-the-asus-r...

I have noticed flicker in loading screens but not in gameplay. Probably cause I haven't tried more than a few games at this point in time.

December 2, 2014 | 03:52 PM - Posted by LimitedColorRange (not verified)

Very useful article, thank you! Do OLED screens suffer from the same problem?

Also, there is one more very widespread problem: limited range color signal that Nvidia GPUs send out when using HDMI and DP at 1080p. More info here:
https://pcmonitors.info/articles/correcting-hdmi-colour-on-nvidia-and-am...

Despite their issues seeming to be isolated to the 1920 x 1080 (Full HD) resolution at present rather than any resolution, Nvidia GPUs are worse offenders for users with affected monitors. They use a ‘Limited Range RGB (16-235)’ colour signal that completely destroys the image quality of the monitor by hampering contrast, colour vibrancy and shade variety. Unlike on AMD GPUs you can’t simply enable the correct ‘Full Range RGB (0-255)’ colour signal universally with a simple drop-down option, either. To add insult to injury a minority of monitors act this way over DisplayPort as well, despite that being a PC only connection where the GPU treating the monitor as a TV simply doesn’t make sense.

December 2, 2014 | 04:51 PM - Posted by Anonymous (not verified)

OLEDs wont have any degradation, so they dont need a min framerate of 30 for gsync or whatever to work.

OLEDs can go as low as 1 or even 0 fps. A true fps = hz. Up to a maximum.

December 2, 2014 | 03:58 PM - Posted by Nightowl (not verified)

If you check the ASUS ROG Forums, the ROG Swift PG278Q has a lot of problems.

http://rog.asus.com/forum/forumdisplay.php?175-ROG-Swift-%28PG%29-ASUS-G...

As of today, I have a one month old ASUS VG278HE monitor even though it does not have GSYNC with 144Hz refresh rate, that plain flat out works with no problems at all.

With all the problems PG278Q has, I honestly wonder why ASUS has the darn thing on the market right now.

December 2, 2014 | 04:46 PM - Posted by Anonymous (not verified)

it's on the market now because of $$$. Which sucks for early adopters but hey, someone has to test it out for the masses.

December 2, 2014 | 06:04 PM - Posted by Fifthdread

I have been putting this monitor through several different games and so far the flickering issue has not been a major problem- but it does exist. I agree with many of you that it isn't a deal breaker, but it does identify an area Nvidia can improve Gsync in later versions or revisions of the technology.

Now if only they could get it working with games in Borderless Window, I would be delighted.

But overall, the Swift has been a great experience for me. Coming from a Qnix 120hz 1440p monitor, it is clearly superior (although significantly more expensive) so I do not regret the purchase. Being on the bleeding edge of the latest technology often comes with a cost. Hardware issues and bugs are common with this sort of thing, even at this price.

If someone wanted a similar experience on a budget (and without Gsync) I would recommend looking at the overclockable monitors such as the Qnix, Catleap, or Overlord Tempest monitors- although you run the risks associated with those monitors as well. Once I experienced gaming in 1440p at 120hz I couldn't live without it. Since I have taken the risks and have owned both Overlord and Qnix monitors, I can offer you some relief by saying I have not had issues with either monitors outside of backlight bleed issues and one or two dead pixels on the overlord - barely visible because of the great PPI on a 1440p display. The Qnix had zero visible dead pixels on my inspection. I could write an entire article on the pros and cons of these monitors so I will stop now before I go to deep into it. Just know that I would do it again if a monitor like the Swift didn't exist.

The big reason I went with the swift was the "wombo combo" of features - low response time / Gsync / 144hz / sexy design / slim bezel. With no software negatives like the Qnix or Overlord, it was no question for me it was what I wanted, even if it was quite an expensive one.

If anyone has questions about the monitor I can answer them.

December 2, 2014 | 06:31 PM - Posted by Anonymous (not verified)

How was the switch from IPS to TN?

"Once I experienced gaming in 1440p at 120hz I couldn't live without it."
That's what I thought too after getting a Catleap, but then I upgraded to a good CRT and now all I can do is wait and pray for OLED. Every single LCD is now almost unusable, especially for motion.

December 2, 2014 | 06:41 PM - Posted by Fifthdread

Wait you upgraded to a CRT? Woah.

But for real, going from IPS to TN was what I was most afraid of, but to be honest the Swift wasn't nearly as bad as I had imagined. I haven't seen a better TN panel out there, so it doesn't kill me like I thought it would. Although the colors are not as accurate and there is color shift, it turned out to be tolerable if I don't slouch in my chair. Some people rave on how bad the color shift is. I say it's still worth it if you are a gamer and you want the response time. It feels faster than the Qnix in that regard, so it's a win for competitive gaming.

But CRT? If it's unusable for motion, have you tried any of the lightboost solutions? How is it unusable?

December 3, 2014 | 06:06 AM - Posted by Anonymous (not verified)

What about contrast when switching from IPS to TN? Do you do anything other than gaming on these displays, and how is the experience? Thanks for the information.

I haven't yet tried lightboost, as prior to the Rog Swift, it was only available in displays that were otherwise terrible. Even now, it seems to be only available in TN panels.

Perhaps "unusable" was a bit too strong of a word to describe all LCDs, but all of them feature significant compromises that are abundantly clear after using a good CRT, which delivers perfect viewing angles, high refresh rates, better colors than IPS, less latency than TN, better contrast than VA, resolutions exceeding 1080p, and motion blur comparable with a lightboosted monitor - all in one display. Instead, you compromise on size, weight, and power consumption - but damn if it isn't a beautiful display to use.

December 3, 2014 | 09:48 AM - Posted by Bubba (not verified)

Which CRT did you get?

December 3, 2014 | 08:07 PM - Posted by Anonymous (not verified)

Mitsubishi Diamondpro 2070SB and a Sony GDM FW900.

December 3, 2014 | 01:05 PM - Posted by Anonymous (not verified)

I hear you. After my FW900 gave up the ghost, I had to find a replacement. That thing was PERFECTION. Ultimately I settled on the 144Hz VG248QE. It's a step down in resolution (1080p instead of 1200, 1440p, 1600p that the FW900 was capable of), but it's been surprisingly good after I calibrated it and tweaked some of the motion settings. If I were given the choice today, I think I would stick with the VG248QE. The picture quality is very good (not as good as the FW900), but the 144Hz gaming is just unbeatable.

December 3, 2014 | 12:48 AM - Posted by Anonymous (not verified)

Hey, can you comment about the 3D vision performance of this monitor??

I have heard of an "inversion" issue when gaming in 3D.

I know most people hate 3D but when done right like in the Batman series and the new Tomb Raider, it can be outright amazing.

Thanks.

December 2, 2014 | 06:15 PM - Posted by Anonymous (not verified)

Certainly seeing this on an ACER 4K gsync monitor in LOTRO loading screens.

I was beginning to think it was me or some back light issues.

Thanks for writing this and please delve further. A fix would be nice but perhaps unlikely. It isn't a deal breaker and it does disappear as soon as the game starts properly.

December 2, 2014 | 08:07 PM - Posted by Anonymous (not verified)

I've had the ROG Swift for a month now and haven't seen the flicker problem yet, however I have seen the following problems:

-the screen has a weird glitch for a brief moment on start up
-on some 24fps videos panning scenes seem very choppy
-light in motion does not turn back on (even with power cycle)

Despite these problems my experience has been good. There were no dead pixels on my monitor, the backlight was uniform, and colours were good. The vertical colour shift can be annoying at times, but the 144hz refresh is a worthy trade off to me. I was considering waiting for a bigger 4K g-sync panel to come out, but I'm glad I didn't, 27" is as large as I'd like to go for gaming and the transition from 1080p to 1440p is great. I hope ASUS/NVIDIA continue to work on resolving these issues on the swift as it is a great monitor.

December 2, 2014 | 08:10 PM - Posted by Anonymous (not verified)

You know this wasn't going to come from Ryan. Tom Petersen would slap him silly.

Allyn brother and wife spotted it on day 1 and Ryan with all his time on the G-Sync monitors has never even mentioned it. Who's looking out for who right ?

For $799 too many buyers are reporting issues on there G-Sync monitors in various forums and some still have issue after multiple exchanges of the monitors.

December 2, 2014 | 08:31 PM - Posted by Allyn Malventano

This article didn't come from Ryan because it was my story to write. I came to him with it, and he hadn't noticed the issue as the games he had tried so far did not present this effect as clearly as my examples. Further, neither Ryan nor NVIDIA made any attempt to bury the story, and I had several conversations with Tom myself about this issue prior to publishing. To be clear - the point you are inferring is about as far from the truth as you can get. 

December 2, 2014 | 10:02 PM - Posted by Anonymous (not verified)

Kind of concerning a company knows this is an issue and provides a statement but isn't even picked up by the person who is suppose to be testing & reviewing these products and has had pre-release hands on experience more than anyone with personal demos from Nvidia.

Your brother and his wife should be hired as product testers if they can weed out apparent issues on the first day when the current tester has had more then 6 months and cant find them. Hire them!!!.

December 3, 2014 | 07:17 AM - Posted by echomike

To be fair, Allyn clearly has freakishly good eyesight and/or visual perception (and so do a few other people, but they're a small minority), as recently evidenced by this article, and the fact that he can spot a 50 ms input lag just by moving the mouse cursor in Windows desktop. :)

December 3, 2014 | 05:00 PM - Posted by Allyn Malventano

There are times where I wish I didn't 'have it', as it makes LCD choices way more complicated for me, but it comes in handy for reviewing them :). That said, my ROG Swift is still on my desk at home. The high resolution and zero latency far outweigh any occasional flicker. Knowing what causes it also seems to help it not bother me. 

December 3, 2014 | 02:32 PM - Posted by Ryan Shrout

Well, despite your view of our how our site and company works, there really isn't "the person" that is assigned to test "these products" all the time. We are a team, and if one person sees and issue that I didn't, then he went into the research direction with it. Also, as Allyn stated, this doesn't show up in all games - the kind of titles I usually play haven't exhibited this effect. Other games like Rift and EVE Online showed it more predominantly. 

Also keep in mind that Allyn's desk is literally 8 ft from mine. We were both working on the issue, finding games that exhibited the problem and I was the one that setup all the calls / communication with NVIDIA on the subject.

Soo....maybe ask some questions before making dumb accusations?

December 3, 2014 | 07:48 PM - Posted by Joe (not verified)

Any you may recall Ryan I originally emailed you about reports I had seen of this. Glad you are guy's are tackling it officially now!

December 3, 2014 | 11:51 PM - Posted by Anonymous (not verified)

the kind of titles I usually play haven't exhibited this effect

There lies the problem. The reviews all bare your name and thus limited by your narrow scope. Maybe now add a RTS game or games with loading screens in them.

my bro FifthDread and his wife both noted a very obvious flicker on their Swifts within the first few minutes of hooking them up. They reported the flicker during game loading screens and mid-game during background content loading occurring in some RTS titles.

The article goes on to say they've been reports of it in various forums but not until Allyn brother and wife reported the issue to Allyn was it ever taken seriously. No one on the team took it seriously until someone related to the team took notice of it with in the few minutes of receiving there monitor.

Credit to Allyn for taking his families concern into account and investigating it if not it would have just been ignored like the various other reports on forums that aren't being reported by family members of the team.

December 4, 2014 | 01:32 AM - Posted by Ryan Shrout

You don't think the games I play have loading screens? Lol

December 4, 2014 | 02:57 AM - Posted by Anonymous (not verified)

A quick google search of "G-Sync flickering" shows results from just one page
ROG/BlurBusters/GeForce/Anandtech/LinusTechTips forums shows

G-Sync flickering on these games dating back to the add-in board.

Thief
Battlefield 4
Company of Heroes 2
Civilization 5
Total War: Rome 2
Drakensang The River of Time
CounterStrike: Global Offensive

I'm sure you have google at your disposal and can expand on this list if you wanted to.

Some of these game you have included in your benchmarks but i'll chalk it up to bad eyesight ofcourse.

December 2, 2014 | 08:48 PM - Posted by Anonymous (not verified)

Very interesting and insightful, thanks Allyn.

December 2, 2014 | 09:03 PM - Posted by Anonymous (not verified)

loving the bezel on this monitor!!!

December 2, 2014 | 09:24 PM - Posted by mLocke

Misinformation expunged. Thanks for everything Allyn.

December 2, 2014 | 10:01 PM - Posted by Rhraziel (not verified)

I've noticed this flicker issue using the gsync adapter. I would notice it a lot during loading screens and in certain cutscenes. I thought it was related to the 25-30 FPS dead zone the gsync adapter has. After reading this, it looks like it's an entirely separate issue.

December 2, 2014 | 11:29 PM - Posted by Allyn Malventano

Both ASUS panels behave the same way in this particular condition. While the retail panels get rid of the 'dead zone' I'd initially reported by more intelligently handling rates <= 30, a complete mid-game stall of a game's render thread will put both the upgrade kit and retail versions into the forced refresh, and it's about as noticable on both. The newer retail version can't be expected to figure out how to properly pace the insertion of additional frames (at a rate >30) when it has nothing to go on (i.e. it has no idea when the next frame might be coming as the frames have suddenly and inexplicably stopped). It's basically doing the best it can with what it has.

I suspect the real solution to this will come from future game engines that can better pace their output. Stalling was never an issue before as there was no visible result when the GPU was at a fixed FPS output. Now that there's a tell, game engine developers might give the engine its own thread during level or content loads, or maybe handle that loading in some other way as to not force a stall condition. In the meantime, if NVIDIA can figure out when this happens in software, they can probably work around it by having the GPU send a constant stream of static frames (at a rate >30 FPS) to help make the game engine stalling less noticable. Those are all just educated guesses based on what I've seen.

December 2, 2014 | 11:46 PM - Posted by Edmond (not verified)

Well, OLEDs arent so terrible as LCDs are.

Im guessing OLED wont need to have that min framerate to not degrade, it could go down to 0 fps even ... as in only refresh where there is a new frame, up to a max fps/hz cap.

This would remove any problems even in laggy loading screens :)

Anyway, absolutely LOVE the article either way!

December 3, 2014 | 05:34 AM - Posted by Anonymous (not verified)

We know how Nvidia likes to take open standards claim they invented them and charge up the wazzoo for them.

Expect them to do it again and take a embedded DisplayPort standard that's already in the works for DisplayPort standards and claim it as their own once again.

Video Electronics Standards Association
2008 eDP v1.0 - seamless refresh rate switching
2011 eDP v1.3 - Panel Self Refresh

I have a feeling G-Sync v2.0 will have PSR and cost more.

December 3, 2014 | 12:46 AM - Posted by MarkT (not verified)

All I gotta say is, Ryan we are watching :-)

December 3, 2014 | 12:57 AM - Posted by Anonymous (not verified)

Hey, can anyone comment about the 3D vision performance of this monitor??

I have heard of an "inversion" issue when gaming in 3D.

I know most people hate 3D but when done right like in the Batman series and the new Tomb Raider, it can be outright amazing.

Thanks.

December 3, 2014 | 05:42 AM - Posted by AMDFANBOI (not verified)

exactly why I'm waiting for AMD's freesync, not rip-off flicker sync.

December 3, 2014 | 02:35 PM - Posted by Ryan Shrout

Well, I hate to point this out, but all variable refresh rate displays would have this problem. And the fact that NVIDIA hasn't found an easy solution to the problem (and they have done a lot more development on G-Sync than AMD has on FreeSync), it will likely remian into next year.

We'll soon see.

December 4, 2014 | 10:24 PM - Posted by Allyn Malventano

Yeah I hate to spoil things, but it's unlikely that AMD will be defying the laws of (LCD pixel) physics with their implementation.

December 3, 2014 | 06:03 AM - Posted by Anonymous (not verified)

I am stupid. Will this problem occur if I take any non-GSync monitor on the market and set its refresh rate to 24 hz in settings?

December 3, 2014 | 02:37 PM - Posted by Ryan Shrout

You're not stupid! No, this won't happen because the refresh rate / redraw rate stays the same throughout content.

December 3, 2014 | 10:27 PM - Posted by Anonymous (not verified)

So its a G-Sync module issue.

The fix will be buy another $800 TN monitor.

December 4, 2014 | 10:26 PM - Posted by Allyn Malventano

Yeah that panel (as well as a GSYNC panel running at 24) will refresh the panel at a multiple higher than this. It varies based on how the manufacturer programmed their display logic.

December 3, 2014 | 07:27 AM - Posted by echomike

Outstanding work! Thanks for putting in the time and effort.

December 3, 2014 | 01:09 PM - Posted by FlyingPenguin (not verified)

I've had the ROG Swift for almost 3 months now and I'm loving it. I have noticed the flicker but the only time I ever see it is during loading screens in some games (notably COD games like Black Ops, Ghosts & Advanced Warfare). It's not an issue for me at all in gameplay.

No issues at all on the Windows desktop. This is with a GTX 760. I must say I am loving the monitor. Can't imagine ever going back to gaming without GSync or some other similar variable refresh system.

BTW: Are any of you using this monitor with a GTX 970 or 980? I would like to upgrade my vid card, but there are a lot of reports on the forums about DisplayPort not working properly on 900 series cards. Doesn't affect DVI or HDMI which most people are using, just DP. People are reporting that the card doesn't detect a DP monitor, and it it's your only monitor, you boot to a black screen. Holding off until I hear this is resolved or that it's not an issue with the ROG Swift.

December 3, 2014 | 02:39 PM - Posted by Ryan Shrout

I have been using 900-series cards without issues; not sure. I have used both retail and reference cards as well.

Your point about the game play not being affect is key to point out. This flickering we are seeing is annoying but only affects games at a random 0 FPS, not during normal playing even if the frame drops into single digits.

December 3, 2014 | 01:41 PM - Posted by Anonymous (not verified)

Without G-sync, running uncapped (no V-sync), 'loading' screens and other static or very basic scenes render at absurdly high refresh rates, in the 1000-2000fps range. This can also be achieved in 3dMark's 'Ice Storm' tests.

Not having a G-sync monitor I am unfamiliar with how framerates are capped, but the flickering may be an artefact of exceedingly high refresh rates rather than low/zero refreshes. Testing with Ice Storm, or a similarly contrived very-low-detail scene may reveal whether the flicker is triggered by lack of refreshing (the same way DP Adaptive Sync works for power-saving in it's original design goal), or through exceedingly high refresh rates.

I only being it up after ending up testing a gtx 970 over VGA, and having very high uncapped framrates cause VERY noticeable rolling flickering. I understand that VGA and DVI operate very differently other than both being a serial pixel stream, but it may be worth looking into.

December 4, 2014 | 10:29 PM - Posted by Allyn Malventano

We've ferified the flicker does not occur at the high rates, only the instantaneous 0 rates. A game load screen renders super fast, but GSYNC actually helps that as it caps to 144 VSYNC-on in that condition. We noticed that even in those instances (loading screen at a 144 FPS), that the engine still stalls as the game loads content, etc, and that stall causes the flicker.

December 3, 2014 | 05:29 PM - Posted by madhatter256 (not verified)

Looks like they need to up some power delivery to the logic board of the monitor than it a software issue.

I wonder if freesync monitors have this issue ;-).

December 4, 2014 | 10:31 PM - Posted by Allyn Malventano

My initial theory on the brightness change was a power delivery issue, but we confirmed it was not the case. From our measurements, this is purely a pixel refresh issue.

December 3, 2014 | 06:45 PM - Posted by Anonymous (not verified)

You gotta love the "it doesn't show up in the games I play" comment.

Sounds like my QA saying "the bug doesn't show up for me". Doesn't mean it doesn't exist... The job of a proper reviewer is to test as many games as possible, since, well, some people will end up playing different games than your usual favorite games. That is what is called a proper and complete review. (Especially all the time you had to play around with that thing). Ah, "internet journalism"... But of course, better write good things, otherwise, no new toy to "review". Lol.

December 3, 2014 | 07:40 PM - Posted by Logun

In the article you said that one of the causes of the issue was due to the TN panel pixels bleeding to white - would a switch to an IPS panel solve this issue then?

December 4, 2014 | 10:34 PM - Posted by Allyn Malventano

It might make the change less apparent (bleeding to black vs. white), but there would still be an apparent change in brightness. IPS bleed rate should be slower, so overall it would probably make it imperceptible, though there would be added side effects of running IPS at 144 (more ghosting vs. TN, etc).

December 3, 2014 | 11:25 PM - Posted by Gregster

I have had this monitor for over 3 months and really do like it and it works well on a single card. The problem I have is multiple cards. I run with 3 Titans and it just isn't smooth or as smooth as a single card I should say. Also, 3D works nicely but Chrome is just a black screen and I have to turn off 3D to see the Chrome browser. I can't really say I noticed the flicker (not saying it isn't there) but I do wish they would get multi cards working well and it isn't just me saying it.

December 4, 2014 | 01:07 AM - Posted by Anonymous (not verified)

I'm glad you commented about the 3D performance.

I have read on the 3Dvision forums about an "inversion" issue when playing in 3D.

Could you please compare the swift to the previous generation of 3Dvision 2 lightboost monitors?

December 5, 2014 | 03:17 AM - Posted by vOidward (not verified)

Can you please look into this issue?:
http://rog.asus.com/forum/showthread.php?50004-PG278Q-vertical-stripes-e...

It's vertical striping on fast high constrast transitions, looks like vertical interlacing. It's not limited to 3D mode as the thread suggests. Here's examples of it in action:
https://www.youtube.com/watch?v=gm7lNyv-frk
http://i.imgbox.com/FRbfR7Cz.jpg

It's listed as issue S2 here: http://www.overclock.net/t/1526956/guide-to-the-problems-with-the-asus-r...

From my experiments with a macro lens, it seems columns of red pixels alternate in brightness ever frame, so even lines of red pixels are on one frame, then odd lines the next which is what's causing this screen door effect. It's most noticeable with either green UI elements or quick orange explosions.

Despite a 15 page thread on the ROG forums, and several other threads about the same issue, no one from ASUS has officially responded about this at all. I just want some acknowledgement of this being a thing that maybe they're at least investigating.

December 5, 2014 | 04:47 AM - Posted by Anonymous (not verified)

Some youtube videos of Asus RoG Swift PG278Q flickering in 2nd mode.

Asus ROG Swift PG278Q Failure
https://www.youtube.com/watch?v=wvn9F_IA6zs

Asus ROG Swift PG278Q issue, problem https://www.youtube.com/watch?v=Umx7ZvDKzdg

Asus ROG swift pg278q - white flickering lines on the right side
https://www.youtube.com/watch?v=Bv0NZhaXLzc

Asus ROG Swift PG278Q Moire Problem / color inversion problem in BF4
https://www.youtube.com/watch?v=29JRmeaAoNw

Asus ROG SWIFT PG278Q Problem
https://www.youtube.com/watch?v=LLETUsNFO68

ASUS ROG SWIFT Monitor failure
https://www.youtube.com/watch?v=q0U8HeOoOMQ

Swift Flicker
https://www.youtube.com/watch?v=ST7FPR6JF9g

Maybe since its Nvidia first time doing a scaler these are the results.

AMD is leaving the monitors scalers up to the companies that have years of experience doing so, maybe that will lead to better QA for us customers at a lower price.

December 6, 2014 | 02:44 PM - Posted by FlyingPenguin (not verified)

I think it's fair to say that this is a monitor for first adopters. It's a lot of money to pay for early tech that's still imature, but I understood that before commiting, and I do not regret the decision.

As I stated above, I never see the flicker except in some game loading screens (COD Black Ops being most noticeable). This monitor is on my gaming rig, not my primary workstation, but I do a lot of browsing and file management on it, and use Remote Desktop, and have not seen flickering in the desktop so far.

Only issue I had was a problem where the monitor would not stay on 144 Hz. The monitor would randomly - sometimes during gameplay - revert to 60Hz, but the video card would continue to send 144 Hz causing the monitor to give an "out of range" error and usually requiring a reboot because the refresh rate toggle on the monitor won't work if the monitor is out of range (bad design there), and I have no secondary display.

Very annoying - only recourse was to run my $800 144 Hz monitor at 60Hz for s month until they fixed it in a subsequent driver update (although I suspect it was a driver hack to workaround a bug in the monitor firmware). It should have been addressed before the monitor's release.

January 8, 2015 | 05:01 AM - Posted by Paul Leventis (not verified)

Gonna go out on a limb here and say this seems quite solvable within the graphics driver. It seems to only noticeable when static content is sent at low frame rates (and even then, only on solid colours).

I imagine Nvidia could do something like this: Timeout and redraw the previous frame after x ms. Currently x seems to be 33. But they could make this value be a function of past history -- each successive timeout causes the interval to decrease, and once a few frames are received at higher rates, reset the timeout to 33 ms. This avoids the problem of not waiting long enough for most of the time -- but solves the problem of long periods of idleness. Nobody will notice a few frames of flicker, or a few frames of slightly-slower FPS when the engine unstalls. But it will make the period during the stall no longer exhibit flicker.

I'd love to see this thing solved, since it instantly bugged me when I got my ROG Swift today (and hence why I found this article). But in the end, its a minor annoyance in an otherwise awesome monitor.

August 15, 2015 | 02:56 PM - Posted by unclelala

Any updates to these problems, and any new Swift monitors in the works?

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