Predator X34 - OC & GSYNC Scanline problem

I received my new X34 last Friday, and I wanted to raise an issue that I have been having with it that I have not seen documented elsewhere in this forum.

The problem is with with GSYNC performance when the monitor is in OC mode. To be absolutely clear, there is nothing wrong with GSYNC performance when the monitor is running at 60hz with OC mode OFF.

When both OC and GSYNC are turned on, the monitor shows alternated light and dark horizontal lines all over the screen. If the GSYNC app is full screen the lines appear all over the screen. If the GSYNC app is running in a window the lines appear all over the screen BUT only if the GSYNC app is the active window.

Apologies for the lack of embedded images, can't figure out a way to get them to work propery - too large for the forum.

This image shows the monitor in normal operation:

http://i.imgur.com/HqOCV5M.png

The very thin lines in the above pic are just the camera picking up the individual rows of pixels, which is not what this problem is about.

This image shows what happens when I activate OC mode and GSYNC at the same time:

http://i.imgur.com/xValz3C.png

The alternating light and dark bands are the problem.

Some further info:

I am running a GTX770, with the latest 358.59 hotfix nvidia drivers. The problem also appears unchanged on earlier drivers. I have tested the monitor on a wholly separate machine running a GTX980. The problem was reproduced identically.

The refresh rate the monitor is running at is irrelevant. With OC ON but GYSNC OFF there is no problem. With OC OFF and GSYNC ON running at 60hz, there is no problem. With OC ON and GSYNC ON running at 60hz (or higher) there is a problem.

It appears in all software that I have tried. The most glaringly obvious incarnation is in Nvidia's own pendulum demo. The lines are quite visible in the shadow underneath the pendulum. Because the demo allows you to easily turn on and off the GSYNC feature, you can make the lines appear and disappear.

But for that issue I would be delighted with the monitor. I can only get 95hz on the GTX770, but it runs 100hz no problem on the GTX980. I have only seen the 50% backlight problem once for only 1-2 seconds, and have no concerns about it. If I reduce the brightness to <30 on the OSD I sometimes get a weird flicker along the top of the monitor in some weird circumstances (like if the Handbrake compression program is the active window). No coil whine. No BLB to speak of. Delightful bit of kit apart from these pesky lines!

Accepted answers

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brighttail

As I reported earlier I was having some issues with G-sync. It seems i'm having similar issues to you.

If I turn it on and choose G-sync in FULL mode, everything is fine 100hz with FPS 100+.

If I turn it on and choose G-sync in WINDOWED mode, the entire computer slows down. The little counter at the top says 100hz but if I start playing a game full screen or windowed mode, i'm down to 10-30Hz with FPS 10-30 as well. The fix it to turn G-sync back to Full mode.

Not sure why this is an issue, but it is.

Iluv2raceit

This sounds like an Nvidia driver issue as you all well know that the 3440x1440 resolution is still considered a non-standard spec and as such is most likely not yet supported officially by G-Sync when in windowed mode. I do remember that there was a similar issue when G-Sync first came out and windowed mode was not yet supported. If you enabled G-Sync while playing a game in windowed mode at 1920 x 1080 or 2560 x 1440, there would have a lot of artifacts and scan lines show up. I hope this helps quell some of your concern. For once, I believe that this particular issue is not the fault of the monitor.

>UPDATE< I just read the latest Nvidia driver release notes and there are still issues with running windowed mode with games regardless of resolution (with and without SLI enabled), so that supports what I initially posted (above). Read more here:

http://us.download.nvidia.com/Windows/358.50/358.50-win10-win8-win7-winvista-desktop-release-notes.pdf

brighttail

I figured this was an Nvidia issue which is why I haven't made a press or demanded an RMA. The monitor is still functioning very well, tho I am still worried about the issue of me turning it on and there is that "crackling" sound. Not sure if that is a speaker issue or a a static electricity issue like the old CRT montiors have. It doesn't look like it is causing any issues but I'll keep an eye on it.

Iluv2raceit

The crackling sound you hear is most likely bleedover from the audio channel on the DisplayPort signal. To get rid of that, you will need to turn off the audio signal going to the monitor's speakers. Go to your "Playback devices" (right click the speaker icon on the lower right corner of the Windows task bar) and disable the DisplayPort audio devices. It should be listed by the name of the monitor (i.e. Acer Predator X34), Just as a reminder, the main difference between DP 1.1 and 1.2 is the audio channel that is available, which is made possible by the extra channels as part of the DP 1.2 standard.

brighttail

Okay, it is now disabled.

We'll see how it works tomorrow.

Thanks for the info.

Fragmachine

Looks like you're seeing the same scanline issue that I have. Except that it appears to be a pure G-SYNC issue. When I got my replacement X34 I made sure to keep the monitor at stock settings which has OC turned off. The scanline issue still appeared as soon as the refresh rate went below 60Hz and is even more noticable when it fluctuates.

striker444

New drivers did not fix or help with the scanlines. I will be filing an RMA with newegg in the near future and be putting this monitor in the rear view mirror. I see others posting about this in the overclock forums with no resolution in sight. I just don't get how they could release this monitor like this, I noticed it immediately. I would say maybe a replacement can fix it but I am reading that even with replacements people are still having the same issue.

Iluv2raceit

Most likely your monitor has a defective G-Sync module. I would RMA immediately for a refund or exchange.

Windholic

I can confirm this scanline issues as well on my X34 - it is very faint but on the Pendulum demo clearly visible. Like others, left side of the screen affected.

Vandragorax

I want to bump this thread since this issue hasn't been addressed in the extensively long "other" X34 thread and this one is more focused.

Could we get any support from Acer reps on this issue at all please? It seems that every unit has this scanlines problem when G-Sync is enabled, and although it's possible to live with it, it's unacceptable not to get a resolution for the problem considering the price point of this monitor.

It could even be a driver issue with the way the NVIDIA drivers are using the module, but either way we need some closure on this please.

Thanks Smiley Happy

Hydroxide

Can also confirm. I received my monitor on friday 2015/11/27 . First thing i noticed was the scanlines. Did some googling and came across lots of forums with people with similar problems.

It is definately very noticeable, occurs mostly when GSync is active even without OC. I consider this a defect and will RMA it shortly unless there's some fix from acer in the immediate future.

For the time being im just running it at 100Hz with GSync off. My GPU/Titan X can deliver high enough framerates in most games so that GSync doesnt add much to the viewing experience, but i bought this monitor due to the fact that it had 21:9, IPS 3440x1440, 100 Hz and GSync which is a comination noone else offers. I wouldn't have bought this for 1415 EUR (in Norway) if i knew that GSync didnt work as intended,

I do love the screen though, im not looking forward to being without it for a week or so while waiting for a replacement =D

Can't seem to find anywhere that Acer have acknlowledged this issue, which i find strange. It's well documented across internet. I'd be happy to provide pictures if that's what it takes,

Cheers

Iluv2raceit

Not every unit has the scanline issue. Mine for one does not exhibit this problem and only has the wake-from-sleep issue. My X34 runs perfectly otherwise. 100Hz rock solid overclock, no coil whine, no flickering, no blue banding, and is pixel perfect. I live in the US and bought my X34 from the US NCIX website in early November. Manufacturing date is September 2015.

Hydroxide

> Not every unit has the scanline issue

Im keeping fingers crossed for a working 2nd one. I have no other issues apart from the scanlines. My friend who bought at the same time as me also has the scanline issue, so with statistics of 2/2 so far im a bit worried of having to cycle through lots of them though. Sucks that there's no assurance in their QA...

Vandragorax

FYI I'm also on 2nd line support with NVIDIA about this to see if they can help crack the problem as well (it might just be drivers, who knows). Will report back if there are any findings.

smoobandit

UPDATE FROM OC:

I sent my monitor back to Acer UK support for a fix. They just returned it to me having, apparently, changed the refresh rate from 95hz to 100hz, and nothing else. Scanlines still present.

On the plus side, I sent it to them on Tuesday and got it back today, so a quick turn around. it is just that it was pointless.

Back in discussions with them.

Ikarusflug

My fourth x34 arrvied today. Has scanlines again. I doubt there are x34 without scanlines, people are just blind.

Iluv2raceit

I'm sorry, but there is NO WAY you could have received four different X34 monitors and all of them have the scanline issue. Something has to be wrong with your hardware setup. You have some kind of electromagnetic interference going on near where you have your monitor. Move your computer and X34 to a different room and try again. Make sure you don't have any electrical devices such as your WiFi router, modem, or cell phone near the monitor. Also, are you using a high speed certified DisplayPort cable that will provide extra shielding against EMI? Don't use the stock DP cable that came with the monitor. Did you also try using a different DP port on your graphics card? And have you tried testing a different graphics card?

Iluv2raceit

I just downloaded and ran the Nvidia G-Sync Pendulum demo tool and it ran perfectly. No scanlines whatsoever. I literally was staring a couple inches away from the screen and verified not one scanline or flickering whatsoever. I am using a GTX980Ti graphics card and a heavily shielded high quality DisplayPort 1.2 cable. I do NOT have any electromagnetic sources near my monitor. My WiFi router sits 40 feet away from my X34 Smiley Happy My X34 maintains a rock solid 100Hz overclock and has no issues whatsoever. In fact, my wake-from-sleep backlight issue seems to have fixed itself - weird. My X34 used to have the issue for the first few weeks I had it, but after doing a hard power reset (unplugged the AC cable for 5 minutes, then plugged it back in and re-entered all of the OSD settings). After doing that, the monitor stopped doing the wake-from-sleep half backlight issue. It just went away. I'll keep an eye on it, but every single cold start from the past week and a half and no occurrence of a half lit backlight anymore. Crazy!

Ikarusflug

Dude iam not the only one who had several x34s and always scanlines. Some of my x34s had it more, some had it less, but all had it. Its not the cable, not some mystical magnetic interference, its the **bleep** monitor. Just read the forums.

Iluv2raceit

The probability of you getting four in-a-row X34 units with scanlines is highly unlikely. You did not address the questions I asked you. The first steps to identifying a potential issue is to troubleshoot and eliminate all other potential causes. It would appear that according to your previous posts that you have NOT done this. No other poster in this forum has received four X34's consecutively with the same issue. Logic dictates the problem is elsewhere and not the monitor.

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