Is there any options that should not be enabled when using the CRT Beam Simulator option?, for example HDR, G-Sync, Adaptive Sync, Automatic Fame Delay etc??
I have a 240hz 4K LG monitor and have enabled the Vulkan driver and Shader Sub Frames option in the video settings as well as selecting the CRT Beam Simulator Shader in the shader folder but to be honest with you I cant see any difference when having this enable or disabled!.
Is there anything else that needs to be enabled??
I donāt think āsync to exact content framerateā works with subframes currently.
At 240 hz, you can try increasing the brightness vs motion clarity parameter in the shader. This will make your image darker but improves the motion clarity because the pixels are black for longer.
Is the āsync to exact content framerateā issue something that will be fixed in the future do you think.
Also does G-Sync still need to be disabled from NVidia Control Panel when using CRT Beam, or has that issue been fixed in RetroArch now?
But other than having that option disabled itās ok to leave the others I mention enabled to cut down on as much latency as possible?.
Iām guessing run ahead is a no go as well then with CRT Beam Simulator ?
I donāt know anything about the nvidia control panel.
I donāt think the VRR/subframe issue will be tackled any time soon. It would greatly complicate the way the feature works internally.
I think the others should be fine, yeah.
runahead should be fine.
In the changelog for Retroarch 1.21.0 (April 29th):
āVIDEO/SHADERS: Allow exact refresh rate sync with shader subframesā
Before, as soon as I enabled subframes, the 'Sync To Exact Content Framerate" option would automatically turn off. Now, it stays on.
well there you go. I clearly havenāt kept up.
Thatās good to hear.
I guess the shader must be working and enabled as I can see a very faint bar move up the screen and if I change the refresh rate in the shader subframe setting then the screen flashes on anything lower or higher than 240hz.
Must just be my aging eyes and canāt notice any difference with it being enabled or disabled
My suggestion: try appending a CRT shader with visible scanlines. If the scanlines stay fairly intact during vertical scrolling, youāre good to go.
Also, Try pausing via ākā key; that way you should be able to pause between subframes. if a 60hz content stay still (and/or you see the dark shade crossing the screen), while you repeating pressing the ākā, then you are definitely using subframes.
Is it possible to prepend this to my MBZ presets, tried it but I am not entirely sure I see a difference. Tried to append it but it creates a mess.
The Mega Bezel cannot be appended or prepended. All additions must be surgically added by @HyperspaceMadness.
I am certain he is keeping an eye on this thread. 
Iāve tried this and all frame look identical, no dimming of the screen or a shade crossing the screen. So maybe the shader isnāt working correctly
Maybe that, maybe subframes are not working either.
To test the latter, try pausing with ākā a game supposed to refresh at every frame (likely an scrolling arcade shoot em up), and verify that the game content (does not/) indeed changes each time you it ākā.
So I have tried 3 arcade games, Final Fight, Alien Storm and TMNT. Have pressed K to freeze the frame and on each press of K key the screen does not alter at all no dark shade crossing the screen.
So for whatever reason I donāt think CRT Beam Simulator is working!?
It doesnāt seem so; if you walk right in FF, does the screen scroll ar every pressure of the ākā key?
That indicates subframes arenāt working.
So start walking right whilst constantly press the āKā key???
what should i be looking for?
frame-advance only advances full frames. it wonāt step through sub-frames.
If subframes arenāt enabled, the shader wonāt show any effect at all: https://github.com/libretro/slang-shaders/blob/master/subframe-bfi/shaders/crt-beam-simulator.slang#L410
ākā steps through subframes, āpā skips whole frames.
My point, @BlockABoots, is that you can see if subframes are working by pressing ā¦k,k,k,k,k,k,ā¦
if you have , say, 2 subframes, you should see:
scrolling,stop,stop,scrolling,stop,stopā¦
If they are not working, you would see: scrolling,scrolling,scrolling,scrolling
EDIT
As @hunterk pointed out, I might be wrong and memory did not served me well, and indeed k key skips whole frames as well.
Sorry for the noise.
So trying @kokoko3k method above (pressing K to advance the fames) wont show the effect and give me an indication that CRT Beam is working as intended???
So I completely removed Retroarch from my system, all traces of it even down to the registry. Downloaded the latest nightly installation and installed. The only options I have chnaged areā¦
Main Menu>Online Updater>Update Core Info Files
Main Menu>Online Updater>Update Assets
Main Menu>Online Updater>Update Databases
Main Menu>Online Updater>Update Slang Shaders
Settings>Video>Output>Video - Enabled Vulcan
Settings>Video>Synchronisation> Enabled Shader Sub-Frame 4 (200/50, 240/60, 280/70 Hz)
Settings>Core> Disabled Allow Cores to Switch the Video Driver
Downloaded the FinalBurn Neo core
Loaded the core
Loaded Final Fight
Pressed āF1ā
Quick Menu>Shaders Enabled Video Shaders
Quick Menu>Shaders>Load Preset>Shader slang>subframe-bfi>crt-beam-simulator.slangp
Press āF1ā to go back to game
Iām still not 100% sure its working as intended. Having the shader enabled or disabled I do not feel that the movement looks or feels any smother at all, surely you should be able to notice it??
Having the shader enabled I can see the faint bar moving up the screen and if I pause the game the screen does become brighter and the slightly duller when resuming the game so it IS doing something Iām just not feeling the benefit of it being enabled
Do I needed to disabled settings in Nvidia CP or my Monitor, like G-Sync or VRR etc?
if you can see it dimming the screen, itās on and working. At default settings, motion clarity should be somewhat better, but you can make it more pronounced at the cost of further reduced brightness by editing one of the parameters. I think itās called something like ābrightness vs clarity tradeoffā or somesuch.