RTS Scanline not locking FPS to refresh rate in some games?!

[GFresha]

So when I used to play Fortnite and run ULMB, I used RTS s-sync to help me out with tearing and set it at -50 while leaving FPS limit in RTS to 0 and FPS limit in Fortnite to unlimited while vsync was off in both game and control panel. With -50 scanline my FPS was at 120 locked to my refresh rate.

Anyways, yesterday I did the same thing with Apex Legends and it is not locking my FPS to my refresh rate? I was still doing the -50 scanline with all vsync off and framerate to unlimited but this time it was locked at 144. I had to set a cap in game properties to 120 so I can lock FPS to hz, anyone knows why the game didn't lock at 120 using RTS only without in game settings?

[RealNC]

Did you create an RTSS profile for Fortnite by mistake and have RTSS disabled there?

[GFresha]

Did you create an RTSS profile for Fortnite by mistake and have RTSS disabled there?

Nope, I have a profile for Fortnite and a profile for Apex and FPS is only capped for Fortnite and Apex. I read online and found Apex is locked in game to 144, so I guess that is the reason why.

[Chief Blur Buster]

RTSS Scanline Sync is extremely difficult with modern games.

1. With capping turned off, you MUST have a framerate range above your refresh rate
2. You should use VSYNC OFF (easiest) with Scanline Sync.
3. You may need to limit RTSS Scanline Sync to older games

Reduce Your Refresh Rate To Cover Your Frametime Spikes
Your refresh rate for RTSS Scanline Sync must be below your 0.1% frametime!

1. Run uncapped VSYNC OFF
2. Measure your frametimes using RTSS
3. Find your worst 0.1% frametime spike (e.g. 10ms)
4. Now divide 1000 by the milliseconds of your biggest frame time spike (e.g. 1000/10ms = use ~100Hz)
5. Reduce your refresh rate to that number. A 10ms frametime spike means you should reduce your refresh rate to ~100Hz.

Reducing your frametime spikes to permit higher refresh rates

1. Reduce game detail
2. Upgrade GPU
3. Stick to older games for RTSS Scanline Sync
4. Some games will give you unavoidable framerate spikes

RTSS Scanline Sync only looks+feels amazing if you keep your entire framerate range above Hz

If you are unable to do this, prefer not to reduce refresh rate, or the compromises outweigh the benefits (refresh rate too low), then please consider using alternative methods such as HOWTO: Low-Lag VSYNC ON

Prioritizing on visuals and consistent glassfloor latency (even if a bit higher than a lower-but-varying lag):
When combined with Scanline Sync, there are situations where reduced refresh rates can look massively better with strobed operation (e.g. ULMB), since perfect 100fps@100Hz ULMB looks CRT quality, while 110fps@120Hz looks jittery/stuttery/harsh/ugly strobing. Oh and if you use motion blur reduction such as ULMB, please don't forget to raise mouse DPI (1600dpi+) and lower in-game sensitivity since ULMB benefits from high-DPI. HOWTO: Using ULMB Beautifully or Competitively.

Hopefully your ~0.1% or ~0.5% frametime spikes permit you to stay at 144Hz or higher, but RTSS Scanline Sync is much easier with older games like Quake, CS:GO, emulators, 60fps-limited console ports, and other games that are more amenable to avoiding frametime spikes that prevent RTSS Scanline Sync from looking amazing.

Rare frametime spike are okay, just try to minimize them
It's okay for your sub-0.1% or sub-0.5% frametime spikes to be worse (the stutter+tearing briefly appear 1 in 1000 frames for 0.1% spikes, and the stutter+tearing appear 5 out of 1000 frames for 0.5% spikes). Regardless, you must have more than 99% of your frame-rate / frame-time range above your refresh-rate / refresh-cycle-time, if you want RTSS Scanline Sync to look beautiful

For more reading, see threads
- RTSS now has new automatic Low-Lag VSYNC ON (raster based)
(easiest)

For advanced readers wanting to get into more advanced RTSS Scanline Sync as a Quick Frame Transport mode
- Optional: Large vertical totals for low input lag
- Optional: Using RTSS Scanline Sync to create Quick Frame Transport.
(harder)

[GFresha]

Oh wow I didn't know about that process. Fortnite is pretty smooth right now with 120hz and 120 fps with s-sync but Apex does look a little jittery so I might perform that process you mentioned.

The issue with Apex is not s-sync not working, I don't see a tear so it is working but when I put -80 for s-sync it doesn't lock my FPS to refresh rate, so I have to put my own FPS cap using RTS.

Fortnite on the other hand, I put -80 for s-sync and it instantly caps my FPS to my refresh rate without me having to cap it using ingame or RTS.

[GFresha]

RTSS Scanline Sync is extremely difficult with modern games.

1. Your MUST have a framerate range above your refresh rate
2. You should use VSYNC OFF (easiest) with Scanline Sync.
3. You may need to limit RTSS Scanline Sync to older games

Reduce Your Refresh Rate To Cover Your Frametime Spikes
Your refresh rate for RTSS Scanline Sync must be below your 0.1% frametime!

1. Run uncapped VSYNC OFF
2. Measure your frametimes using RTSS
3. Find your worst 0.1% frametime spike (e.g. 10ms)
4. Now divide 1000 by the milliseconds of your biggest frame time spike (e.g. 1000/10ms = use ~100Hz)
5. Reduce your refresh rate to that number. A 10ms frametime spike means you should reduce your refresh rate to ~100Hz.

Reducing your frametime spikes to permit higher refresh rates

1. Reduce game detail
2. Upgrade GPU
3. Stick to older games for RTSS Scanline Sync
4. Some games will give you unavoidable framerate spikes

RTSS Scanline Sync only looks+feels amazing if you keep your entire framerate range above Hz

If you are unable to do this, prefer not to reduce refresh rate, or the compromises outweigh the benefits (refresh rate too low), then please consider using alternative methods such as HOWTO: Low-Lag VSYNC ON

Prioritizing on visuals and consistent glassfloor latency (even if a bit higher than a lower-but-varying lag):
When combined with Scanline Sync, there are situations where reduced refresh rates can look massively better with strobed operation (e.g. ULMB), since perfect 100fps@100Hz ULMB looks CRT quality, while 110fps@120Hz looks jittery/stuttery/harsh/ugly strobing. Oh and if you use motion blur reduction such as ULMB, please don't forget to raise mouse DPI (1600dpi+) and lower in-game sensitivity since ULMB benefits from high-DPI. HOWTO: Using ULMB Beautifully or Competitively.

Hopefully your ~0.1% or ~0.5% frametime spikes permit you to stay at 144Hz or higher, but RTSS Scanline Sync is much easier with older games like Quake, CS:GO, emulators, 60fps-limited console ports, and other games that are more amenable to avoiding frametime spikes that prevent RTSS Scanline Sync from looking amazing.

Rare frametime spike are okay, just try to minimize them
It's okay for your sub-0.1% or sub-0.5% frametime spikes to be worse (the stutter+tearing briefly appear 1 in 1000 frames for 0.1% spikes, and the stutter+tearing appear 5 out of 1000 frames for 0.5% spikes). Regardless, you must have more than 99% of your frame-rate / frame-time range above your refresh-rate / refresh-cycle-time, if you want RTSS Scanline Sync to look beautiful

For more reading, see threads
- RTSS now has new automatic Low-Lag VSYNC ON (raster based)
(easiest)

For advanced readers wanting to get into more advanced RTSS Scanline Sync as a Quick Frame Transport mode
- Optional: Large vertical totals for low input lag
- Optional: Using RTSS Scanline Sync to create Quick Frame Transport.
(Harder)

Actually Chief, If I am using ULMB along with RTTS scanline sync (s-sync) isn't the recommended to have FPS=hz?

But in your post you mention:

1. Your MUST have a framerate range above your refresh rate

1) I assume this only applies if I am only using s-sync and not ULMB mode along with it correct? Because right now I am using ULMB mode and I am under the impression that FPS=hz along with a higher DPI is the best to go with that mode. And that, if I have tearing on ULMB then I can simply enable s-sync and set an offset (usually -80 works for me) and then I would be solid or am I wrong here?

2) If I wasn't running ULMB, I would probably just run g-sync with vsync on in control panel and a 3 FPS cap below my refresh rate so I would not need to do that process you mentioned above correct? Or would s-sync be even more fluid than g-sync?

3) The reason why I made this thread is because I was under the impression that If you have ULMB enabled and enable s-sync and set an offset, then s-sync would cap your frames to your refresh rate without having to use in game cap or RTTS cap, the s-sync offset in it self capped it. This was true for Fortnite, my FPS was not capped in game or RTTS but when I put -80 offset, it instantly got capped through s-sync to 120 FPS because my refresh rate is 120 hz to enable ULMB.

The issue is that, when I did this same thing to Apex legends, the FPS was not capping to my refresh rate with s-sync offset alone, I had to also use RTTS FPS cap to cap 120 FPS.

TLDR:

Fortnite no game cap + no RTTS cap + s-sync -80 = my fps to my refresh rate

Apex no game cap + no RTS cap + s-sync -80 = my FPS above my refresh rate

Apex no game cap + RTS cap (120 fps) + s-sync -80 = my fps to my refresh rate

Really it is silly but I want to know why was s-sync good enough on its own to cap my FPS to my refresh rate in Fortnite but not in Apex? Why did I have to use an additional FPS cap on top of s-sync to get my FPS to my refresh rate?

[Chief Blur Buster]

But in your post you mention:

1. Your MUST have a framerate range above your refresh rate

I meant:

1. With capping turned off, you MUST have a framerate range above your refresh rate

Before turning on any frame rate capping.

And yes, fps=Hz. Any framerate under Hz, means it's not possible to maintain perfect fps=Hz. Well, at least ~99.9% of the time.

[GFresha]

But in your post you mention:

1. Your MUST have a framerate range above your refresh rate

I meant:

1. With capping turned off, you MUST have a framerate range above your refresh rate

Before turning on any frame rate capping.

And yes, fps=Hz. Any framerate under Hz, means it's not possible to maintain perfect fps=Hz. Well, at least ~99.9% of the time.

For example Fortnite has 120 FPS all the time cos of the game it self and so ULMB works so perfect and fluid.

But, Apex on the other hand is sometimes 120 and sometimes 100 and fluctuates between 100-120, would it be better to set my refresh rate to 100 and cap FPS to 100 in Apex or just use another sync method? Because the game kind of looks jittery...

[Chief Blur Buster]

But, Apex on the other hand is sometimes 120 and sometimes 100 and fluctuates between 100-120, would it be better to set my refresh rate to 100 and cap FPS to 100 in Apex or just use another sync method? Because the game kind of looks jittery...

Both are legitimate options.
(A) Try 100Hz ULMB
(B) Try another sync mothod (e.g. variable refresh rate)

It's a matter of different priorities of pros/cons (motion clarity, fluidity, latency, etc).

[GFresha]

I unlocked Apex to 162 FPS lock and used gsync instead of 100 hz and 100 fps ULMB and man it was way too smooth. I feel like FPS games prob don't benefit from ULMB? Or my eyes too used to 165 hz i don't know... For example Fortnite ULMB is absolute beauty.