RTSS Scanline Sync HOWTO

[Milincho]

Keep the vertical resolution the same. What needs to be done is increasing the vertical total and making sure that increases the vbi. Try using the vertical total calculator option. What's the refresh rate you're aiming for?

50Hz and 60Hz. I managed to get it working, but every time there are frametime inconsistencies/spikes tearing appears again all over the screen. So this method is supposed to either work only for perfectly stable fps and frametimes, or if you prefer to have tearing (and stutter) as opposed to stutter with normal vsync?

[RealNC]

50Hz and 60Hz. I managed to get it working, but every time there are frametime inconsistencies/spikes tearing appears again all over the screen.

Switch to front edge or back edge sync in RTSS settings and set a frame limit that EXACTLY matches your refresh rate in addition to enabling scanline sync. This is called "hybrid scanline sync" and it can help keep the tearline stable. See:

https://forums.guru3d.com/threads/msi-a ... st-5951576

[Kuscheln_Hammer92]

Why would he need the hybrid sync? Wouldn't either the front sync or the back sync be enough along with the sync flush being set to 1 or 2 depending on the API his game is using? I thought that decreases the space the tear travels. Also, if his load is high enough and he can't maintain that fps, that'd definitely do him in, right? I suppose we should also ask the native max hz of his monitor in hopes of finding why he can't get himself a larger vbi, right?

[RealNC]

Why would he need the hybrid sync? Wouldn't either the front sync or the back sync be enough along with the sync flush being set to 1 or 2 depending on the API his game is using? I thought that decreases the space the tear travels. Also, if his load is high enough and he can't maintain that fps, that'd definitely do him in, right? I suppose we should also ask the native max hz of his monitor in hopes of finding why he can't get himself a larger vbi, right?

When GPU load gets high, tearline gets erratic even if FPS can be maintained. Hybrid mode helps with that.

[Kuscheln_Hammer92]

Hybrid is for those with the high GPU load, okay, thank you. I'll keep that noted for sure. I was wondering, then, what about lower GPU load caused by CPU bottleneck? If a cpu usage is so high causing you bottlenecking is that what the passive CPU mode is best for?

[RealNC]

I was wondering, then, what about lower GPU load caused by CPU bottleneck? If a cpu usage is so high causing you bottlenecking is that what the passive CPU mode is best for?

Passive CPU wait mode allows the CPU to save some power, but has otherwise no impact on game perf. The CPU utilization of busy wait mode (the opposite of passive) is only spinning the CPU in an idle loop while the game is blocked and wouldn't be using the CPU anyway. However, the busy loop prevents the CPU from entering low power states.

Passive mode is 90% passive. The last 10% is still a busy loop. See:

https://forums.guru3d.com/threads/why-i ... st-6119756

To change the default of 90%, see:

https://forums.guru3d.com/threads/why-i ... st-6122064

[Kuscheln_Hammer92]

I appreciate your explanation of the passive on vs off. But do you know much in regards to GPU low utilization due to high CPU usage? Essentially, trying to ask seeing how I can get higher framerates on some games with scanline sync off, but turning it on reduces greatly the amount of fps my PC produces in some games like Halo MCC. I can reach 200-250fps consistently in halo 2 anniversary with it off and GPU utilization at 80%.With it on it won't even reach the locked hz of the monitor. It will vary and sometimes longer at half that! No matter the in game settings or with or without the anticheat enabled. RTSS' framerate cap w/o sync causes same performance issues. Game just doesn't like RTSS. I'm even seeing less frames with the game in the og Xbox mode rather than remaster but at least it maintains fps=hz.

I'm thinking of just setting a max refresh rate to maybe 120hz, using in game limiter to 240fps, and then using AMD's enhanced sync. All this effort because I really like using the backlight strobing lol. I just need to see test results on the lag that produces in-game.

Also attaching the dxvk 2.1 resulted in breaking the game. Lol

[Milincho]

50Hz and 60Hz. I managed to get it working, but every time there are frametime inconsistencies/spikes tearing appears again all over the screen.

Switch to front edge or back edge sync in RTSS settings and set a frame limit that EXACTLY matches your refresh rate in addition to enabling scanline sync. This is called "hybrid scanline sync" and it can help keep the tearline stable. See:

https://forums.guru3d.com/threads/msi-a ... st-5951576

Will try, thanks for the tip.

To clarify: my display is an european Epson EH-TW9300 (6040UB in USA) projector. It is 1080p (3LCD) native.
I'm using a RTX4080 with a Ryzen 9 [email protected] in Windows 11 and I am testing this method in Jedi Survivor (UE4) playing in stereoscopic 3D using Reshade + SuperDepth3D shader. This UE4 game is horribly optimized, so even with the 4080 at 70% usage or less it can't maintain stable 60fps in many areas.
I'm using 1440p DLDSR resolution. Can't reach stable 60fps in many places (no matter the resolution), so I resorted to use the 50Hz mode and 50fps, which it can do at least 98-99% of the time.

I've been using normal vsync + RTSS frame limiter to stabilize frametimes for a long time in many games, but most modern games (specially UE games) have shader and traversal stutters no matter what. And also microstutters with every little spike for whatever reason. I'm not hugely interested in the lag improvement, but if these Scanline Sync or "hybrid scanline sync" methods can offer a less stuttery result with an invisible tearline or barely visible at all it would be a very interesting improvement for me.

[Milincho]

50Hz and 60Hz. I managed to get it working, but every time there are frametime inconsistencies/spikes tearing appears again all over the screen.

Switch to front edge or back edge sync in RTSS settings and set a frame limit that EXACTLY matches your refresh rate in addition to enabling scanline sync. This is called "hybrid scanline sync" and it can help keep the tearline stable. See:

https://forums.guru3d.com/threads/msi-a ... st-5951576

Just tried both "Front edge" and "Back edge" with frame limit to 50.00 but result is the same. Tearing appears on the upper part of the screen, and when I try to move it out of the screen to make invisible with Ctrl+Shif+Up it gets to a point where it starts to appear on the lower part of the screen too, even before disappearing from the top area.

This is the resolution I am using, maybe I'm doing something wrong here?

[Kuscheln_Hammer92]

I wonder if that 3d effect software is the issue here. Try running it natively without all the 3d effects. How large is the tear across the screen when it showing? Like vertically how far is it jittering?