MiSTer Freesync and LG CX TVs - Not Possible?

[AtomicShroom]

I can certainly attest that FreeSync on my Samsung Q80R doesn't change anything with MiSTer. No matter what I do or which vsync mode I select, or whether I enable FreeSync or not, I have simply been unable to get a perfectly smooth scrolling in Super Mario World (or any other game on the SNES core for that matter). There's always one-frame stutters here and there periodically. It's really distracting.

[mistahsnart]

Just to add to this:

Hooked up my MiSTer to my LG 32GK650F, which is a 48-144 Freesync monitor (up to 100hz via HDMI). Exact same things that both myself and Escape-To-88 has observed on our LG CX displays. Super Mario World scroll hitch, Samurai Shodown 15khz flicker, etc. Leading me to believe it's either an LG thing, or that it's starting to show cracks in the myth that a Freesync display does indeed work 'perfectly'.

But that's not to say it is not better than my old fixed 60hz displays. Just not the super-smooth life Freesync offers.

I am NOT an expert, so always ready to be wrong, is it possible that unlike Freesync/VRR these displays can't do anything but full steps for devices that don't support it? Like instead of 57.24, it has to choose 57 or 58? Stuff like 15khz shadows not being AS apparent as it is on my 60hz display makes me think that.

Mind the strike throughs. Doing new testing.

[Escape-To-88]

Interesting. Even more surprising I've just been running the Mister through my cabs. I have two Taito Egret 2 candies both with nanao ms9 crts in. All the Neo stuff is perfect as you'd expect. What isn't perfect is Super Mario World. It has the same issue as it does when on the OLED. This leads me to believe I've never noticed it. However I find that also tough to believe. I've been playing it since release and have owned at least 8 SNES console variations including the NT and I have never noticed it before. Very odd. Not sure what to make of it.

[mistahsnart]

I've got two CRT televisions, 2 models of SNES, the MiSTer, and now I'm inclined to check later.

[zakk4223]

I have a 160hz VRR LG gaming monitor and Samurai Shodown IV scrolling looks good, SamSho II select screen scrolling looks good, shadows look good etc.

There is one peculiar thing about my display though is that it seems to want to lock the input and output frame rate regardless of if it claims to have freesync on or not. There may be another setting I have to dig deeper for, not sure yet.

If someone is saying Super Mario World has that issue on a CRT then maybe there's something else going on with that core?

[mistahsnart]

Alright. Got a solid 30 minutes due to a last-minute meeting cancel.

Back to the LG LCD Freesync monitor:
Added in the scroll tests from folks for SamSho 2 and 4 intros. Smooth as silk. Shadows are correct as well now. Why? I had the overdrive cranked from playing FPS games so what I was seeing was overshoot. This isn't a high-end monitor. Turned it down for a clearer look. My bad. I'm not a very good testing methodology person.

BUT: still seeing that screen hitch in Super Mario World that was observed earlier. Both on this LCD and the LG CX. I am not a big Super Nintendo person, so I wouldn't of known it was wrong until it was pointed out. So I'm certainly not the best to chase that.

Also of note: this LG LCD monitor reports a proper 59khz in the info panel for Neo Geo (doesn't show any middle steps), so that's already different than the CX OLED.

[Insert Disk Two]

What's the exact model of the LG monitor please? Does it handle 50hz frequency?

[FoxbatStargazer]

Edit: I take back any advice. I have a hard time seeing discrepencies on 60hz panels, even ones I know shouldn't have freesync. Even the 240p test suite drop shadow and scroll tests. Its obvious they are struggling with 50hz content though, even a freesync monitor that should have it in its range.

[mistahsnart]

What's the exact model of the LG monitor please? Does it handle 50hz frequency?

LG 32GK650F - was in my first post. No idea about 50hz. I never use it.

[Escape-To-88]

I've got two CRT televisions, 2 models of SNES, the MiSTer, and now I'm inclined to check later.

I'll die of shame if the jerkiness is in the original cart. I've finished at least 25 times and played it hundreds of times, mainly on orignal carts so am intrigued what you find! Interestingly if I run it on my Nvidia Shield on Retorarch it does some odd drops, not like what we are seeing. I always assumed it was a refresh rate mis match and other junk due to inaccuracy I'm now wondering if it's the pausing issue mishandled and it is on the original cart. I'm going in to check the Switch online version now, it's bugging me no end. I should check Super Mario on the NES too really as that core operates at 60.10 also.

Edit: I've never noticed it but there is certainly something at the exact same points on the Switch online version. I'm wondering if it just appears more pronounced on the Mister than what I'm used to? Anyhow, Samurai Shodown II is the best test of all this. I think I'm going to stick to the arcade cabs for now and keep an eye if anyone else finds anything about the CX as it clearly can't match exact frame rates, which seems to be an issue when a sub £200 monitor can do it! Perhaps the answer is to use a Freesync PC monitor for console cores ultimately? Or at least until there is some kind of CX firmware patch, which I suspect won't happen. I did look at the SNES issues here: viewtopic.php?f=18&t=1718 and am going to run some more CRT-based tests to see if many other games exhibit the odd jitter. I'd actually forgotten about the de-jitter mod for certain consoles, but I thought that was largely to eliminate behaviours when connected to a Frame meister or OSSC.

[FoxbatStargazer]

Its not uncommon for emulators to emulate original system speed and then buffer the output to exactly 60hz, instead of adjusting the system speed to line up with modern displays. Tons of retroarch cores do that by default and I'm not surprised if Nintendo's emulators do the same.

I've got a great "certified gsync-compatible" freesync monitor here that reports the correct input refresh rate but I can't figure out if it is displaying near-60 cores correctly. It sure as heck does not display 50hz right, obvious jerky scrolling, even though the range over HDMI is supposed to be 48-120... I'm still not really convinced that freesync is a magic bullet here and would caution spending money on stuff you can't return easily.

[mistahsnart]

I've got two CRT televisions, 2 models of SNES, the MiSTer, and now I'm inclined to check later.

I think I'm going to stick to the arcade cabs for now and keep an eye if anyone else finds anything about the CX as it clearly can't match exact frame rates, which seems to be an issue when a sub £200 monitor can do it! Perhaps the answer is to use a Freesync PC monitor for console cores ultimately? Or at least until there is some kind of CX firmware patch, which I suspect won't happen.

Or, OR, hear me out...

Don't let the minor bumps, which I'll admit I didn't even notice until you showed me what to look for, bother you and enjoy owning one of the best modern 4k televisions for all the other reasons it excels over just about any other type of display. Having a gaming PC or a VRR/120hz console running on it is divine.

[Escape-To-88]

I've got two CRT televisions, 2 models of SNES, the MiSTer, and now I'm inclined to check later.

I think I'm going to stick to the arcade cabs for now and keep an eye if anyone else finds anything about the CX as it clearly can't match exact frame rates, which seems to be an issue when a sub £200 monitor can do it! Perhaps the answer is to use a Freesync PC monitor for console cores ultimately? Or at least until there is some kind of CX firmware patch, which I suspect won't happen.

Or, OR, hear me out...

Don't let the minor bumps, which I'll admit I didn't even notice until you showed me what to look for, bother you and enjoy owning one of the best modern 4k televisions for all the other reasons it excels over just about any other type of display. Having a gaming PC or a VRR/120hz console running on it is divine.

It's a great set for sure. Have my Synologly NAS feeding my Shield 4K remux files...looks amazing for film, throughly enjoying it for that stuff. Been running the MiSTer on one of the Egrets and I'm generally really impressed, even the console stuff feels great and reminds me of the old Super System arcades I used to play as a kid...minus the sticky out pads I've compared certain games to GroovyMAME one after the other and there are definite improvements from the MiSTer, which is ace.

[Insert Disk Two]

Anyone tested Samurai Shodown 4 intro Japanese text for stuttering on the LG CX?

[atrac17]

I find it strange that no one has commented/noticed this before, especial Atrac17.

That's because I use a $400 LG UN73000 at 5x... I haven't played with my CX. But it does VRR, it wouldn't sync to my modelines if it didn't. Also, who knows what they are pushing to the CX.

I can tell you that the Samaria Spirits IV test isn't using my ini settings. Stuttering doesn't occur. Shimmering doesn't either. Scroll on vertical looks improper with the publichsed vertical scanlines. I've fixed that issue for myself. I play on CRTs anyways. Anything I've put out is just to help future proof or those without a CRT.

I don't check here often.

[FoxbatStargazer]

I finally found a test that works for me: The Sonic 3 save select screen. Any chaos emeralds on your save there alternate every frame between pure white and an emerald sprite. As the genesis is slightly below 60hz it's a pretty good way to test how your display handles something slightly off of 60 hz.

As a control condition, use vsync_adjust=0 with one of the built-in 60hz modes. (making your own modeline can yield weird refreshes.) With vsync_adjust=0 I can see the emeralds briefly flash a solid color once every minute or so, this is due to Mister forcing the output to exactly 60hz and having to double a frame every now and then. Then set vsync_adjust=2 and see if it disappears.

Was surprised to see this work for all of my displays old and new, freesync or non, even the ones that handle 50hz very badly, the 60hz emeralds stay purely transparent in vsync_adjust=2, where they flash occasionally in vsync_adjust=0. So there is some idea of displaying slightly off-spec refresh even in modern displays.

That said Neo-Geo being down at 59 hz is more of an outlier, and the trouble with NES/SNES is they are actually slightly fast instead of slightly slow like most systems. I think some bright, flickering object is more reliable/easier to detect than scrolling or even a drop shadow; maybe someone can recommend some game for these systems that makes things as easy to detect as Sonic 3 on Gen/Mega.

[Harrumph]

This was curious. Foxbats test does show the CX does proper framelock with genesis core at least (sub-60Hz system). EDIT: or wait Foxbat wasn’t testing on a CX were you?
The issue with SMW or nes/snes in general I would presume would have been picked up by some prominent people in the scene, like retrorgb. I know he has an older model (C9 maybe?). Maybe reach out to him on twitter and I’m sure he would look into it.
Also, why aren’t people using 240p test suite to test the SNES stutter issue, it has both scroll and drop shadow tests?

An additional question, I obviously don’t own an LG CX (yet), but how does it work if you simply disable freesync (if that is even possible)?

In any case, freesync has never been a prerequisite for smooth frame-locked display anyway, it’s just a matter of whether frame-lock is allowed or not by the display software, and it can vary even within models from same manufacturer. I have had two Philips sets which never did frame conversion, but another one I tested did enforce frame conversion to 60Hz.

[FoxbatStargazer]

I do not have a CX (unfortunately) but I was able to test on some Sony 4Ks, the 950H and the 850C, and so far just the Genesis core. These Sony TVs can also handle mister's mode 9 (1080p/50hz) somewhat smoothly but I think its just doing a pulldown to 120hz. Scrolling looks pretty good but the 240p test suite drop shadow is extra unstable/flickery. Which is why I'm not sure scrolling is always the most reliable test...

[Ashfall]

Has anyone figured out a fix to this? I just replaced my old Panasonic plasma with an LG C1 and am having this issue now. The old plasma handled NES/SNES and Neo-Geo refresh rates perfectly. But the LG converts to 60.0 for the NES/SNES and 59.94 for the Neo-Geo. Tried a bunch of things but could not get anywhere. So at this point I assume it's just a limitation of LG, unless something buried in the service menu can get around it.

[paulbnl]

Has anyone figured out a fix to this? I just replaced my old Panasonic plasma with an LG C1 and am having this issue now. The old plasma handled NES/SNES and Neo-Geo refresh rates perfectly. But the LG converts to 60.0 for the NES/SNES and 59.94 for the Neo-Geo. Tried a bunch of things but could not get anywhere. So at this point I assume it's just a limitation of LG, unless something buried in the service menu can get around it.

So you are getting frame drops? My LG B9 has no issues with SNES or NeoGeo AES. Neogeo on MVS mode (59.17Hz) does have frame drops.

[Ashfall]

So you are getting frame drops? My LG B9 has no issues with SNES or NeoGeo AES. Neogeo on MVS mode (59.17Hz) does have frame drops.

Yes, noticeable frame drops in Super Mario World on SNES and Metroid on NES. I wasn't looking for it, but noticed the frame drops in Metroid right away after getting the C1. I'll try a few other things tonight when I have time.

It would be great if there were an option like what the Analogue jailbreak has where it slightly adjusts the system speed to a 60.0 refresh rate for cases like this.

[Ashfall]

I'm beginning to think the frame drops may only be specific to a few games. I did some more testing and here are my findings:

Nothing in the TV settings changes the behavior. I checked way more things than can be listed here.
General MiSTer settings do not affect the frame drops. Resolution, color depth, vsync_adjust 0,1,2 change nothing.

Focusing on only NES and SNES, I tried the Test Suite ROMS and a few games.

NES

• 240p Test Suite (PD) v0.21 pinobatch.nes
  All scrolling tests are perfectly smooth, vertically and horizontally at every speed.
  Drop shadow test is perfect.
• Metroid - Start of new game, run right to door, then left repeatedly. Frame skip happens in the exact same places, regardless of timing. Did not notice that pattern before. Tested with and without extra sprites.
• Final Fantasy 1 - no frame drops anywhere walking in towns, with or without b-button dash.
• Super Mario Brothers - no frame drops noticed in first stage, walking or running.

SNES

• 240p Test Suite (PD) Artemio v1.03.sfc
  All scrolling tests are perfectly smooth, vertically and horizontally at every speed.
  Drop shadow test is perfect.
• Super Mario World - Stage 1 (to the right of Yoshi's house on world map) - walking to the right shows no frame drops, but running to the right and left shows frame drops. They seem to be in the same general areas, but not exactly like Metroid. Tested with and without turbo CPU.
• Final Fantasy II and III - Intros have lots of vertical scrolling and some horizondal. No frame drops.

I'll connect the MiSTer to my old plasma later to see if the frame drops in Metroid are happening there and I just didn't notice it before. That was the first game I fired up right after getting this new LG C1 OLED, and I noticed the frame skipping right away. Maybe just coincidence combined with OCD? I'll also try some other games and see if there are more that show frame skipping.

And I didn't notice any frame skipping in Neo-Geo or Genesis. I tried Samurai Showdown IV scrolling intro text and Sonic background scrolling.

[Ashfall]

A few more NES games observations.

Gradius - No frame drops (use invincible cheat).
Castlevania - No frame drops, running back and forth on first screen.
Castlevania III - During vertical scrolling intro, frame drops approximately every 14 seconds.
1943 - Stage 1 frame drops in background water, but not clouds or ships or anything else (use invincible cheat).

[paulbnl]

NES

• 240p Test Suite (PD) v0.21 pinobatch.nes
  All scrolling tests are perfectly smooth, vertically and horizontally at every speed.
  Drop shadow test is perfect.

It must be the games then. If the scrolling is perfect on the 240p test suite then the TV is not frame skipping. I am assuming the TV is on Game mode with Motion interpolation off.

vsync_adjust=0 should cause frame skipping in the scrolling test.

[Ashfall]

It must be the games then. If the scrolling is perfect on the 240p test suite then the TV is not frame skipping. I am assuming the TV is on Game mode with Motion interpolation off.

vsync_adjust=0 should cause frame skipping in the scrolling test.

Game mode off/on makes no difference. Yes, with vsync_adjust=0 there is frame skipping in the scrolling test.

I connected the MiSTer to my old Panasonic plasma TC-P65ST60, ran all the same tests and got the same exact results as on the LG C1.

So we are in agreement, it must be the games. Metroid prompted me to search for this issue on this websute and go down this rabbit hole. I guess I was scrutinizing my new C1 too much and noticed things that were always there in the game.

[Dafoof]

Just found out about this thread, good to see that I'm not the only one who has run into trouble with VRR support on TV (this time on a Samsung QD-OLED)! I posted some observations there:
viewtopic.php?t=6667
Wonder if the artefact I see is linked to that problem you encountered, this would actually make sense: I get constant screen tearing (always at the exact same position, for a given non-60 refresh rate, and it is more in the middle of the screen for 50Hz than for 57Hz), as if Mister correctly communicates the expected refresh rate, but then the actual display happens at a different one, maybe still 60 like you.