Stutter issues with two GTX 980s (not TI) in two-way SLI with two UHD monitors and one HD monitor

[DRaGZ]

Hello all!

 

So I am using two GTX 980s (not TI) in two-way SLI with two UHD monitors (one is technically a TV) and one HD monitor, all running at 60 Hz. 

 

TL;DR

 

1. What exactly does "Activate all displays" do? I get the same benchmarking results as with "Disable SLI" yet all my displays are still displaying when "Disable SLI" is chosen, and "Activate all displays" shows up as SLI being disabled, so what's the difference? 

 

2. Is the GTX 980 simply incapable of driving two UHD displays comfortably? Currently it's stuttering when playing low intensity games like Overwatch, even when running Netflix or YouTube videos. The stutter happens when two UHD displays and one HD displays is hooked up into one GTX 980, stuttering with or without SLI, but the stutter stops when the UHD displays are split across the two cards.

 

3. Is the GTX 1080 capable of driving two UHD displays comfortably without stuttering during gameplay?

 

Full post below:

 

Currently, the setup runs very stuttery. Videogames like Overwatch will drop the framerate where it didn't before, and even Netflix and YouTube will run stuttery. 

 

Before, I had a setup where it was one UHD monitor and two HD monitors with SLI activated, this setup worked just fine, no issues whatsoever. 

 

Currently, all monitors are coming out of one 980, I know this is the only way for "Maximize 3D performance" SLI to work because it's basically funneling all of the power into one card. 

 

When I turned off SLI and put one UHD display on one card and the other UHD display + the HD display on the other, performance stopped stuttering. 

 

The "Activate all displays" option looked intriguing, because it claims it'll use SLI and Multi-GPU rendering when necessary, but cursory benchmarking in Arkham City and Arkham Knight seemed to demonstrate this was not the case: Arkham City with "Maximize 3D performance" chucked out around 83 FPS, "Activate all displays" and "Disable SLI" ran around 65 FPS, and Arkham Knight showed that only around 4000 VRAM was available when "Activate all displays" was selected but around 8000 VRAM when "Maximize 3D performance" was selected. 

 

I'm also not exactly sure what "Activate all displays" is even doing. When I choose "Disable SLI" outright, even with the displays split across the two cards all displays are still activated. When I do "Activate all displays," SLI is still shown as disabled. So what exactly the heck is it doing?

 

Another thing is that even with SLI disabled, the video still stutters when all of the displays are coming out of one card. When the UHD displays are split between the two cards using "Activate all displays" it plays fine. So this doesn't seem to exactly be a micro-stuttering issue happening because of SLI, it seems to be a limitation of the 980 hardware to drive two UHD displays at 60 Hz regardless of SLI. 

 

What I would ultimately like is for the stuttering to stop happening with my double UHD + one HD display setup, but it seems a shame that I have to do so by turning SLI off.

 

Worse comes to worse, I can turn the SLI off and split the UHD across two the two cards since my primary focus for this machine is as an editing rig for freelance and personal video editorial work, but it seems a shame that I can't take advantage of the power of SLI for gaming since it's definitely a noticeable difference. 

 

Is this a limitation of the 980 card in general? Is the hardware bad at running two UHD displays even with SLI enabled? 

 

In the future, when the GTX 1090 TI inevitably drops, I was looking to get two so I could run these in SLI as well. Do you think this setup would be capable of running two UHD displays + an HD setup without the stutter? Specifically, if the current GTX 1080 can run two UHD monitors without issue, surely the TI would be fine, right?

 

I am mainly interested in the mechanics of why this is occurring, any insight would be super helpful. Thank you!

[TheRandomness]

Stutter..? SLI..? I think we've found the problem. 

[Senzelian]

I wonder what you mean by "stutter".
A low framerate or is it literally stuttering even tho your framerate is relatively smooth?

I had two GTX 980s in SLI and I wouldn't want to play on one UHD monitor, let alone two. They're just not powerfull enough for a good gaming experience at that resolution if you're not going to lower some settings significantly.

And when did the problem start to occur? Did it just happen out of nowhere or have you done something to your system in that time?

[DRaGZ]

4 minutes ago, TheRandomness said:

Stutter..? SLI..? I think we've found the problem. 

Well, read further.

 

I previously had a setup with SLI, two HD monitors and one UHD monitor, no stuttering at all. The same rig, just swapped out one of the HD monitors for a UHD TV.

 

Even when SLI is off, the exact same stutter issue occurs if all of the displays are coming out of one card. Only when the UHD displays are split across two cards does the stuttering stop.

 

And this isn't stuttering in Arkham Knight or anything. This is stuttering when playing a YouTube video.

 

I was originally led to believe that the GTX 980 was capable of running two UHD displays just fine, so it's disappointing that this seems to be a limitation of the card. 

[DRaGZ]

17 minutes ago, Senzelian said:

I wonder what you mean by "stutter".
A low framerate or is it literally stuttering even tho your framerate is relatively smooth?

I had two GTX 980s in SLI and I wouldn't want to play on one UHD monitor, let alone two. They're just not powerfull enough for a good gaming experience at that resolution if you're not going to lower some settings significantly.

And when did the problem start to occur? Did it just happen out of nowhere or have you done something to your system in that time?

Ah, questions!

 

For instance, in Overwatch, I have V-sync on and it maintains a solid 59 FPS but sometimes dips to around 53 with a noticeable stutter when it does so (it's not just a framerate drop, the screen literally freezes for a quarter-second). 

 

For YouTube/Netflix videos, every 1-2 seconds results in a frame skip. I can't watch freaking SD episodes of Good Eats without stutters. 

 

Before I had the two UHD monitors, I actually ran UHD games just fine with two other HD monitors as well. Arkham City, for instance, would push past 90 FPS in SLI when running at UHD and everything maxed out, it was actually pretty awesome. I also would have videos running on another monitor and it would still play well. There was a really weird issue where the game would flicker when NOT playing at 4K, but that eventually resolved when I updated to Windows 10. 

 

I have literally changed nothing about the system other than add the UHD TV. I feel like it's the GTX 980 struggling to drive two UHD monitors by itself even when boosted through SLI.  

 

Like I said, when I split the UHD monitors across the two cards the stutter is gone, but I do miss the performance gain in videogames

 

I searched through these forums more, and maybe it's a pixel limit? Apparently a 780 has a pixel limit of 11000x2160?

I currently have my other 4K TV oriented stacked on top of my other 4K monitor...if I literally oriented them side-by-side, would that make it render it more easily, crazy as that may sound? I guess I'm shooting in the wind here, lol. 

[TW1ST3R]

You should be able to run two 4K monitors off the one card just fine for normal use.  Just did a quick test and used DSR to push both my monitors to 3840x2400p and experienced no stutters on Youtube, or other normal usage.  (970 SLI setup here).  Not exactly apples to apples comparison there, but I'm like 95% sure you shouldn't be having issues using 2x 4K monitors for normal work usage.

 

I'm no expert but It could be a hardware issue, maybe a problem with the cables, monitors, or display connectors on the GPU.  You could try swapping cables or switching card positions so you're connected to the other one to troubleshoot that.  You are using Displayport or DVI right? Because HDMI 1.4 only does 4K 30Hz. but that's only an issue if your monitors are HDMI 1.4, the GPU itself is HDMI 2.0

 

or

 

It could be a driver issue.  Have you tried a clean install of your GPU drivers?  If not, you might want to try that as it usually resets all the settings to default, which might be good if some setting got messed up along the way.

 

Edit:  From what I understand, Activate all displays activates the ability to use any/all video connectors on either card, but disables SLI. So you don't want that checked.  If you want SLI you need to either select Maximise 3D performance (SLI active in games for one monitor), or Span displays with surround (SLI active in games for one giant combined desktop)

[Senzelian]

7 minutes ago, DRaGZ said:

Ah, questions!

 

For instance, in Overwatch, I have V-sync on and it maintains a solid 59 FPS but sometimes dips to around 53 with a noticeable stutter when it does so (it's not just a framerate drop, the screen literally freezes for a quarter-second). 

 

For YouTube/Netflix videos, every 1-2 seconds results in a frame skip. I can't watch freaking SD episodes of Good Eats without stutters. 

 

Before I had the two UHD monitors, I actually ran UHD games just fine with two other HD monitors as well. Arkham City, for instance, would push past 90 FPS in SLI when running at UHD and everything maxed out, it was actually pretty awesome. I also would have videos running on another monitor and it would still play well. There was a really weird issue where the game would flicker when NOT playing at 4K, but that eventually resolved when I updated to Windows 10. 

 

I have literally changed nothing about the system other than add the UHD TV. I feel like it's the GTX 980 struggling to drive two UHD monitors by itself even when boosted through SLI.  

 

Like I said, when I split the UHD monitors across the two cards the stutter is gone, but I do miss the performance gain in videogames

 

I searched through these forums more, and maybe it's a pixel limit? Apparently a 780 has a pixel limit of 11000x2160?

I currently have my other 4K TV oriented stacked on top of my other 4K monitor...if I literally oriented them side-by-side, would that make it render it more easily, crazy as that may sound? I guess I'm shooting in the wind here, lol. 

Okay. Now I think I start do understand.
I'll just go through the usual quastions at this point, even tho it might seem annoying.

Have you tried ...

• ... different outputs, cables and inputs on your devices? DisplayPort? HDMI?
• ... to connect both displays to the second card?
• ... switching both cards around?
• ... to uninstall all drivers with DDU (DisplayDriver Uninstaller) and installed them again?

And if you've done all of that, did you notice any significant changes?

[FPS-Russia]

SLi.

[Senzelian]

SLi.

Very helpful, really...

[FPS-Russia]

Just now, Senzelian said:

Very helpful, really...

I am glad i could help.

[DRaGZ]

11 minutes ago, TW1ST3R said:

You should be able to run two 4K monitors off the one card just fine for normal use.  Just did a quick test and used DSR to push both my monitors to 3840x2400p and experienced no stutters on Youtube, or other normal usage.  (970 SLI setup here).  Not exactly apples to apples comparison there, but I'm like 95% sure you shouldn't be having issues using 2x 4K monitors for normal work usage.

 

I'm no expert but It could be a hardware issue, maybe a problem with the cables, monitors, or display connectors on the GPU.  You could try swapping cables or switching card positions so you're connected to the other one to troubleshoot that.  You are using Displayport or DVI right? Because HDMI 1.4 only does 4K 30Hz.

 

or

 

It could be a driver issue.  Have you tried a clean install of your GPU drivers?  If not, you might want to try that as it usually resets all the settings to default, which might be good if some setting got messed up along the way.

I'll try the card swap first then try the DDU.

 

For the record, the UHD computer monitor is running through Displayport 1.2, the HD monitor is running DP 1.2 (it's a color correction monitor) and the UHD TV is a Vizio that uses HDMI 2.0 to drive 60 Hz.

 

I appreciate these suggestion, I think I was too stubborn to even try it without the advice! haha

 

EDIT: Also, for the record, I tried the crazy ides of orienting them in the Display Settings as side by side all the way when in SLI, no dice. 

[DRaGZ]

So...uh...

 

I switched out all of the plugs from one graphics card to the other, no dice.

 

I uninstalled all Geforce drivers using DDU, reinstalled the newest drivers...the issue is now slightly worse...

 

Before, when running in "Activate all displays" or "Disable SLI" there was no stutter in YouTube/Netflix videos. Now there is very occasional stutter. 

 

So at least something happened? Hahha.

 

I am encouraged that you were able to use two 970s in SLI with UHD displays without these issues, TW1ST3R, since that means it must be resolvable somehow...

 

I'm going to keep troubleshooting. 

 

I've tried running Blu-Rays too, now, through PowerDVD 16, this seems to actually run BETTER in SLI mode than when disabled. When it was off it stuttered a lot, when it was turned on, it only stuttered once at the beginning of a Blu-Ray then played fine for the next ten minutes. 

 

Premiere Pro also seems to be playing back my footage without stutter, so that's good news. 

 

I'm wary of swapping the two cards' slots because I don't really see how they could really affect this (there's also a Thunderbolt card in there in a funny position, so I'd rather not disturb it and go through a ton of trouble.

 

Grrrrrrrrrrrrrrrrrrrrrr...

[DRaGZ]

Weird update:

 

PowerDVD was playing back with weird stuttering, I turned off hardware acceleration, and it's now fine.

 

I also opened Netflix in Firefox instead of Chrome like I was usually doing, now it runs with little to no issues (I think any hiccups I see is literally downloading issues).

 

The fawk. 

 

EDIT: Played a game of Overwatch with SLI on, it still stutters slightly but nothing terrible. 

 

I think something about the double UHD displays makes hardware acceleration in video-based applications more fragile unless it's optimized. Stutteriness that occurs in Chrome (which I think uses a kind of hardware acceleration for video playback) does not occur in Firefox, and similarly such stutteriness does not happen in PowerDVD with the hardware acceleration turned off. There has been no stutteriness in Premiere Pro, but that's like because Adobe optimizes the shit out of their programs for NVIDIA cards.

 

I can live with the slight bits of stutter in Overwatch for now, it's not...horrible..just annoying. 

 

I may revisit this later. My highest priority was to make sure freaking videos can play back correctly on this rig, they seem to be okay now...

[TW1ST3R]

12 hours ago, DRaGZ said:

Weird update:

 

PowerDVD was playing back with weird stuttering, I turned off hardware acceleration, and it's now fine.

 

I also opened Netflix in Firefox instead of Chrome like I was usually doing, now it runs with little to no issues (I think any hiccups I see is literally downloading issues).

 

The fawk. 

 

EDIT: Played a game of Overwatch with SLI on, it still stutters slightly but nothing terrible. 

 

I think something about the double UHD displays makes hardware acceleration in video-based applications more fragile unless it's optimized. Stutteriness that occurs in Chrome (which I think uses a kind of hardware acceleration for video playback) does not occur in Firefox, and similarly such stutteriness does not happen in PowerDVD with the hardware acceleration turned off. There has been no stutteriness in Premiere Pro, but that's like because Adobe optimizes the shit out of their programs for NVIDIA cards.

 

That's really odd.  I have no problems with hardware acceleration.  But you can turn it off in Chrome by going to Settings > Show Advanced Settings > (Scroll to bottom) System > Uncheck Use Hardware Acceleration.

 

Question.  Does the problem persist if you unplug the 1080p monitor?  According to the specs on Nvidia's website the maximum resolution supported is 5120x3200.  Just wondering because the total resolution for all three monitors exceeds that.  But I don't know whether that actually means anything.

• 5120x3200 = 16,384,000 pixels
• UHD = 3840x2560 = 7,516,800
• HD = 1920x1080 = 2,073,600
• 2xUHD + 1xHD = 7,516,800 + 7,516,800 + 2,073,600 = 17,107,200

Second question.  Does SLI work properly with games if you only have one monitor plugged in?  If so you can probably just get away with turning off the monitors you don't need while gaming by using "Windows key + P" to change from extend displays to primary display only.