Screen tearing after playing Zelda LTTP for multiple hours. [Fixed]

[AtomicShroom]

Hey guys,

Something strange occurred this weekend. I decided I wanted to beat Zelda LTTP in one sitting, start to finish. It started out just fine too, as normal. I have never, ever witnessed screen tearing on my MiSTer before. Then after about 4 to 5 hours of continued play, the game started exhibiting random/intermittent screen tearing, which left me very surprised.

Is this a known/suspected issue? I assume most people on here never use their MiSTer for very long sessions. Have cores been tested in this capacity?

[PikWik]

well, i can say ive never experienced something like that,
and most days my mister is on for very long periods of time (8-10 hours with several different cores running)
but, i also run the SNES core playing kaizo rom hacks for around 4-5 hours fairly often.

to troubleshoot further tho, we would need something other than "SNES core has tearing after a couple hours".
is this happening after you switch from an input source (HDMI 1, then switch to HDMI 2, and then back to HDMI 1)

i also dont know anything about your mister.ini or your TV setup, so that would be my first question.
and im also guessing youre using your mister on a modern TV and not a computer monitor, yes?

[AtomicShroom]

well, i can say ive never experienced something like that,
and most days my mister is on for very long periods of time (8-10 hours with several different cores running)
but, i also run the SNES core playing kaizo rom hacks for around 4-5 hours fairly often.

to troubleshoot further tho, we would need something other than "SNES core has tearing after a couple hours".
is this happening after you switch from an input source (HDMI 1, then switch to HDMI 2, and then back to HDMI 1)

i also dont know anything about your mister.ini or your TV setup, so that would be my first question.
and im also guessing youre using your mister on a modern TV and not a computer monitor, yes?

Have you played a single rom for 4-5 hours straight?

If I see it happening again, I will try switching inputs. Obviously I seldom have this amount of free time to investigate this. And yes, I’m using my MiSTer on a very modern TV. My .ini has nothing special. 720p with 0.5 integer scale and vsync mode 0. I have *never* seen it screen tear before.

[grizzly]

It can be so much that is the problem it will be hard to determine what is wrong.
One thing i do think about is heat, Do you have a heatsink/fan/case/watercooler/oilbath? Or nothing?
And yes case can be a big point if it is a kinda small enclosed case! Or even a case with some vents but maybe build up heat after hours?

Then we have the screen/tv can that be at a point where it is close to overheating/doing some strange stuff, or maybe something else in the chain?
Or maybe it is one hdmi connection somewhere in the chain that when heated up does not have a 100% connection anymore, this can sometimes be solved to switch cable or even turn "it around" as in the end in the mister is now in the tv and vice-versa.
I did solve getting a "green static buzz" at 5% off the left side on the screen that happened sometimes and only a resync (as in switch hdmi channel/replug/turn off/on) fixed it, but turned the cable around and has worked flawlessly for over 10 year after.

And what about a quick restart as in when pressing reset on a real snes, or a reboot of the core, reboot of the mister?
If for example a restart does not fix it but a mister reboot does will probably tell some aliens (you know the ones trying to kidnap the people of earth using the mister as main pacifier weapon ) at least something.
And will the fault appear if the mister is on with the game or do you have to play? Is also something that probably will tell something

[PikWik]

Have you played a single rom for 4-5 hours straight?

yes of course, ive grinded thru kaizo hacks for quite a while in one sitting.
4 hours with 1 rom loaded and no switching cores/restarting is something i probably do the most on the mister.
my current setup im using now is with a computer LCD monitor.

but,
when i was using my 4K TV (samsung q70r) i would notice weird screen issues, like parts of the bottom of the screen "catching up" and/or video artifacts if i set vsync_adjust=2. and then later, i noticed jumping/frame drops if i switched inputs of my TV from HDMI 1 to HDMI 2 and then back to HDMI 1. if i would switch inputs while a game on the mister was running, i would have to restart the core to get rid of the frame drops (which is what im assuming is the TV having trouble going from the weird refresh rate of a retro console, to a 60FPS computer, and then back to the retro console's refresh rate)

after switching to using a computer monitor, i have not seen something like that again, and so my first suspect is your TV.
perhaps a firmware update for your TV could fix this, but chances are, its just the way your TV handles retro.

[AtomicShroom]

Have you played a single rom for 4-5 hours straight?

yes of course, ive grinded thru kaizo hacks for quite a while in one sitting.
4 hours with 1 rom loaded and no switching cores/restarting is something i probably do the most on the mister.
my current setup im using now is with a computer LCD monitor.

but,
when i was using my 4K TV (samsung q70r) i would notice weird screen issues, like parts of the bottom of the screen "catching up" and/or video artifacts if i set vsync_adjust=2. and then later, i noticed jumping/frame drops if i switched inputs of my TV from HDMI 1 to HDMI 2 and then back to HDMI 1. if i would switch inputs while a game on the mister was running, i would have to restart the core to get rid of the frame drops (which is what im assuming is the TV having trouble going from the weird refresh rate of a retro console, to a 60FPS computer, and then back to the retro console's refresh rate)

after switching to using a computer monitor, i have not seen something like that again, and so my first suspect is your TV.
perhaps a firmware update for your TV could fix this, but chances are, its just the way your TV handles retro.

Yeah I have the Samsung Q80R, so the inner workings are identical. I have the latest firmware. I also saw the issue you mentioned with the bottom of the screen tearing up and "catching up" when using vsync_adjust 2, which is I'm using vsync_adjust 0 instead unfortunately. It causes a frame hiccup every once in a while, but that's way less distracting than the bottom screen tearing up constantly. About frame jumping/drops, absolutely make sure to disable "Game Motion Plus" under Game Mode settings if you haven't. This setting regularly made 60fps games drop to 30 fps for short periods of time, then back to 60, while also causing strange pixel deformations in 2D games. I don't even know why this mode exists, it's just broken through and through. And since Black Frame Insertion (LED Clear Motion) is locked behind that mode, it makes that also unusable with 60fps games. Absolute trash from Samsung. They clearly did not test these settings with stable 60fps content. Or if they did and signed off on it, it's just shoddy.

I did not switch inputs once during my LTTP playthrough, which is why I'm so puzzled as to why it worked perfectly fine for some 4-5 hours straight, and just then decided to start acting up out of nowhere. Why would it?

It can be so much that is the problem it will be hard to determine what is wrong.
One thing i do think about is heat, Do you have a heatsink/fan/case/watercooler/oilbath? Or nothing?
And yes case can be a big point if it is a kinda small enclosed case! Or even a case with some vents but maybe build up heat after hours?

Then we have the screen/tv can that be at a point where it is close to overheating/doing some strange stuff, or maybe something else in the chain?
Or maybe it is one hdmi connection somewhere in the chain that when heated up does not have a 100% connection anymore, this can sometimes be solved to switch cable or even turn "it around" as in the end in the mister is now in the tv and vice-versa.
I did solve getting a "green static buzz" at 5% off the left side on the screen that happened sometimes and only a resync (as in switch hdmi channel/replug/turn off/on) fixed it, but turned the cable around and has worked flawlessly for over 10 year after.

And what about a quick restart as in when pressing reset on a real snes, or a reboot of the core, reboot of the mister?
If for example a restart does not fix it but a mister reboot does will probably tell some aliens (you know the ones trying to kidnap the people of earth using the mister as main pacifier weapon ) at least something.
And will the fault appear if the mister is on with the game or do you have to play? Is also something that probably will tell something

Yeah I know it's a longshot, I was just wondering if it's something anyone else had seen. My MiSTer is in an aluminum case with a fan, so I doubt heat is a factor. But I thought about it too, because I figure that's probably the variable that's prone to change over time. Next time it happens (if it ever does), I will try turning off the TV and/or reconnecting the HDMI cable (or even use another one) to see if it solves the issue. Thanks for the suggestions!

[ioev]

I can confirm that I've seen screen tearing after playing Breath of Fire II, though I'm not sure how long I was playing before I saw it. I'm on a Samsung plasma, I have heatsink and fan and no case on MiSTer. I normally see a bit of frame skip every few seconds or so, and I feel like the screen tear replaces the frame skip. I wonder if the problem is only really noticeable on games that scroll in both the x/y directions?

[AtomicShroom]

Welp I had the same thing happen again while playing Tales of Phantasia for around 4 hours straight. Was absolutely fine before that, then it started tearing.

As someone suggested, I tried disconnecting and reconnecting the HDMI cable and it didn’t do anything.

I loaded another SNES game and it persisted. I switched to the NES core and loaded a game, and that made the tearing go away. Switched back to the SNES core and loaded a game and it was fine.

Doesn’t seem like the MiSTer itself is the problem if switching cores makes the issue go away. Whatever it does when initializing a core fixes it.

This seems to be the repro steps so far:

- Use vsync_adjust 0
- Load a SNES game.
- Let it run for over approx. 4 hours.
Result: It will start tearing.

[Hyper Space Squid]

Have you tried changing the CPU speed to Turbo under the hardware setting on the Snes core? This fixed some of the screen tearing issues i was having on a select number of games.

[AtomicShroom]

Have you tried changing the CPU speed to Turbo under the hardware setting on the Snes core? This fixed some of the screen tearing issues i was having on a select number of games.

Why would I do that? The goal here is 100% accuracy. I shouldn’t have to turn that on to resolve an issue that shouldn’t exist in the first place.

[grizzly]

Agree, but IF it fixes it it can possibly lead to narrowing down the cause and a fix!

[rhester72]

I suspect your display itself is losing sync after extended periods of use.

Pick a game you've seen tearing on _where it does it even in demo mode_, and I'll leave it up and running on mine overnight to see if it manifests.

[Hyper Space Squid]

Agree, but IF it fixes it it can possibly lead to narrowing down the cause and a fix!

Exactly, turn on turbo or not, I'm just offering a solution to a problem.

[PikWik]

i know theres a wall of text to read above, but i have basically the same TV as original poster, Q70r, and would notice odd tearing/artifacts/issues as well.

this was remedied by switching to a dedicated computer monitor (Acer Nitro XF243Y Pbmiiprx) instead of a consumer HDTV.
and yes, i play specifically SNES for extended periods of time (mostly super mario world rom hacks where grinding for hours on end is the norm)

my first thought is/was that its just the way those 4K samsung's handle retro, unfortunately

I suspect your display itself is losing sync after extended periods of use.

[ash2fpga]

Hmm, intersting if it could be the display itself with the tearing issue.

[AtomicShroom]

i know theres a wall of text to read above, but i have basically the same TV as original poster, Q70r, and would notice odd tearing/artifacts/issues as well.

this was remedied by switching to a dedicated computer monitor (Acer Nitro XF243Y Pbmiiprx) instead of a consumer HDTV.
and yes, i play specifically SNES for extended periods of time (mostly super mario world rom hacks where grinding for hours on end is the norm)

my first thought is/was that its just the way those 4K samsung's handle retro, unfortunately

I suspect your display itself is losing sync after extended periods of use.

Yes you will see tearing and artifacts *all the time* if you use vsync_adjust 1. This is not what I’m talking about. I’m talking about using vsync_adjust 0 where for the first ~4 hours it will work perfectly fine, then suddenly start tearing out of nowhere. Is this what you experienced? Otherwise it might just be that you were using vsync_adjust 1, which is a different issue (and yes in this case the TV is 100% to blame).

[AtomicShroom]

Update:

I can confirm it happens with the NES core as well, so it’s probably MiSTer-wide and not isolated to the SNES core. Again same: Let a game run for around 4 hours, then tearing starts to occur.

[rhester72]

@AtomicShroom: Can you specify one game that exhibits this even when not being actively played so we can duration-test ourselves (without playing for 4 hours)?

[paulbnl]

As someone suggested, I tried disconnecting and reconnecting the HDMI cable and it didn’t do anything.

I loaded another SNES game and it persisted. I switched to the NES core and loaded a game, and that made the tearing go away. Switched back to the SNES core and loaded a game and it was fine.

Doesn’t seem like the MiSTer itself is the problem if switching cores makes the issue go away. Whatever it does when initializing a core fixes it.

Disconnecting and reconnecting the HDMI cable should have fixed it if the problem is in the TV. The problem is in the MiSTer scaler. I have reproduced it after leaving the Zelda intro running over night with your settings (vsync_adjust=0, 720p).

The normally dropped frame is replaced by a moving tear from bottom to the top every 10 seconds. This indicates the scaler is selecting the wrong frame buffer. I have verified this by checking the latency. Normally the latency is 2 frames with vsync_adjust=0 but in this tearing mode there is only 1 frame of latency.

This is easiest to see with the grid scroll test in the 240p test suite. I am now leaving that running in 1080p to see if it happens in that resolution.

[rhester72]

@paulbnl I'd like to reproduce this myself - which Zelda?

[jlancaster86]

I'm not sure if this is related, but I've started having issues with my Samsung Q80T since it updated to firmware 2014.1 today. I had been using "vsync_adjust=1" just fine for the last six months, but now it (and "vsync_adjust=2") results in the frame skipping and weird tearing/ripples at the bottom of the screen others have mentioned in the thread. It seems "vsync_adjust=1" can temporarily work after some fiddling (like turning Game Mode on and off), but it looks like I'm stuck using "vsync_adjust=0" for now.

[paulbnl]

@paulbnl I'd like to reproduce this myself - which Zelda?

Zelda a Link To The Past USA version with vsync_adjust=0, video_mode=0, vscale_mode=2. I suspect it does not matter which game you run.

I left the SNES 240p test suite running for more than 5 hours with vsync_adjust=0, video_mode=8, vscale_mode=0 and I don't see tearing yet. It could be that integer scaling is required to trigger the tearing.

[PikWik]

interesting results here, paulbnl & jlancaster!
these refresh/sync issues seem to be common to these samsung 4K TVs and the MiSTer.

i can say, i was noticing very similar things to what lancaster is describing, but after switching to a computer monitor, those bottom screen "catching up" weird artifacts have gone away (with vsync_adjust=2). i do want to also mention that vsync_adjust=2 is a must for me, and is part of the reason why i got a MiSTer, to play games in their original speed/refresh rates easily with as little lag as possible. setting - vsync_adjust=0 which uses triple buffered (2 frames​) at 60hz (compatibility mode) is not something i want to use my MiSTer with, and kind of defeats the purpose of FPGA, imo.

and i can confirm, i have left my MiSTer running for several hours, both in SNES and letting a CPS2 game run in attract mode for hours on end, and dont see tearing on my computer monitor. but if there is something the MiSTer could do to "update/handshake" the HDMI scaler, im all ears!

paulbnl is thinking the vscaler is losing sync at some point and that after several hours the scaler is "selecting the wrong frame buffer," adding that disabling vscale in the INI appears to fix the issue. i personally use a NTSC monitor, vscale_mode=3, vsync_adjust=2 @ 1080p

[paulbnl]

It is important to note that there are 2 different issues here:

1. Tearing with vsync_adjust=0: Caused by MiSTer scaler. This is visible on all displays/capture cards.
2. Tearing with Samsung and vsync_adjust=1/2. Caused by Samsung. Tip: Do not buy Samsung

and i can confirm, i have left my MiSTer running for several hours, both in SNES and letting a CPS2 game run in attract mode for hours on end, and dont see tearing on my computer monitor. but if there is something the MiSTer could do to "update/handshake" the HDMI scaler, im all ears!

The tearing issue is with vsync_adjust=0 and you are using vsync_adjust=2 so you won't see tearing on your monitor.

paulbnl is thinking the vscaler is losing sync at some point and that after several hours the scaler is "selecting the wrong frame buffer," adding that disabling vscale in the INI appears to fix the issue. i personally use a NTSC monitor, vscale_mode=3, vsync_adjust=2 @ 1080p

I don't know if disabling vscale fixes the issue. It needs more testing but as you can imagine testing is very slow with having to wait 4-5 hours every time.

[aberu]

I would often see this with Final Fantasy III for the SNES (Final Fantasy VI). I haven't played that in awhile and it was really intermittent. Would only happen after long hours of play, I can confirm that. I have a Samsung TV as well, and my signal chain is not that great, MiSTer --> HDMI Splitter --> HDMI Passthrough on Receiver --> Receiver's ARC HDMI Out <--> Samsung TV's ARC HDMI In.

[ItalianGrandma]

I have seen some tearing as well in various games, but it was on my AOC monitor and it’s happened with NES, SNES and I believe other cores as well. It’s very intermittent though, and I’m not sure what steps I could take to reproduce it. I know when it did happen, I wasn’t playing for four hours and a reboot always fixed it. I’m also fairly certain I’ve seen it with both vsync=0 and vsync=2.

[AtomicShroom]

@AtomicShroom: Can you specify one game that exhibits this even when not being actively played so we can duration-test ourselves (without playing for 4 hours)?

I tried with Super Mario World this morning and I was able to reproduce it by just leaving it idle for around 4 hours. Since the demo scrolls to the right it’s very easy to notice.

Disconnecting and reconnecting the HDMI cable should have fixed it if the problem is in the TV. The problem is in the MiSTer scaler. I have reproduced it after leaving the Zelda intro running over night with your settings (vsync_adjust=0, 720p).

The normally dropped frame is replaced by a moving tear from bottom to the top every 10 seconds. This indicates the scaler is selecting the wrong frame buffer. I have verified this by checking the latency. Normally the latency is 2 frames with vsync_adjust=0 but in this tearing mode there is only 1 frame of latency.

This is easiest to see with the grid scroll test in the 240p test suite. I am now leaving that running in 1080p to see if it happens in that resolution.

Thanks for confirming @paulbnl! What you’re describing is *exactly* what I’m witnessing.

Can this be fixed by the MiSTer team? Surely there is a way to output a signal that will not tear. I’ve played my SNES Classic for an ungodly amount of hours and never once have I seen it tear, and it’s also sending a 720p signal. So certainly the TV is not at fault here. There has to be a way for MiSTer to send a proper stable signal?

[ash2fpga]

The scaler source is here:
https://github.com/MiSTer-devel/Templat ... /ascal.vhd

Not exactly a simple thing.

I started looking at the rescaling logic a bit a while back to try to understand it better, but I was only interested in reproducing a single frame, to compare against/verify PolyphasePreviewer results, and not anything temporal. (I still have yet to get back to that. )

[paulbnl]

Thanks for confirming @paulbnl! What you’re describing is *exactly* what I’m witnessing.

Can this be fixed by the MiSTer team? Surely there is a way to output a signal that will not tear. I’ve played my SNES Classic for an ungodly amount of hours and never once have I seen it tear, and it’s also sending a 720p signal. So certainly the TV is not at fault here. There has to be a way for MiSTer to send a proper stable signal?

Sure it can be fixed but so far it has been difficult to pin point the issue. Yesterday I left the 240p test suite running for 8 hours in 1080p mode without tearing. Today I have left it running for 10 hours at 720p without tearing.

Just now I left Super Mario World running for about 1.5 hours at 720p and it started tearing.

Either this is a coincidence or Super Mario World can trigger it and not the 240p test suite which would be very strange.

[jlancaster86]

It is important to note that there are 2 different issues here:

1. Tearing with vsync_adjust=0: Caused by MiSTer scaler. This is visible on all displays/capture cards.
2. Tearing with Samsung and vsync_adjust=1/2. Caused by Samsung. Tip: Do not buy Samsung

Yeah, the two issues seem to be unrelated. I've created a separate thread for discussing the Samsung TV issue here.