RTSS Scanline Sync HOWTO

Everything about input lag. Tips, testing methods, mouse lag, display lag, game engine lag, whole input lag chain, VSYNC OFF vs VSYNC ON, and more! Input Lag Articles on Blur Busters.
User avatar
RealNC
Site Admin
Posts: 2863
Joined: 24 Dec 2013, 18:32
Contact:

Re: RTSS Scanline Sync HOWTO

Post by RealNC » 25 Jun 2019, 10:01

Abiak wrote:Ok so scanline sync 60 and fps limit 60?
No. Just scanline sync. Scanline sync is the FPS limiter. Do not apply any other FPS limiter on top.
SteamGitHubStack OverflowTwitter
The views and opinions expressed in my posts are my own and do not necessarily reflect the official policy or position of Blur Busters.

Abiak
Posts: 39
Joined: 02 Sep 2018, 12:50

Re: RTSS Scanline Sync HOWTO

Post by Abiak » 25 Jun 2019, 12:12

Thanks.
Chief Blur Buster wrote: 8. Enable the Scanline Sync hotkeys, it makes calibration easier (arrow keys to move the tearline UP/DOWN)
Enable the Hotkeys to manually move the tearline up/down Add SyncHotkeys=1 to your config file to enable shortcuts. Hold CTRL+SHIFT while using UP/DOWN arrow to move the tearline up and down.
Can you explain this? Which config file?


Edit: nvm done...

mist
Posts: 17
Joined: 05 Feb 2019, 14:05

Re: RTSS Scanline Sync HOWTO

Post by mist » 29 Oct 2019, 17:29

This thread must be sticked at top.

MrFix
Posts: 2
Joined: 01 Dec 2019, 14:02

Re: RTSS Scanline Sync HOWTO

Post by MrFix » 01 Dec 2019, 14:10

My only problem with this whole thread is that it doesn't actually tell you how to enable the feature in RTSS, even though it's supposed to be a how-to! :lol:

MrFix
Posts: 2
Joined: 01 Dec 2019, 14:02

Re: RTSS Scanline Sync HOWTO

Post by MrFix » 01 Dec 2019, 14:21

How does one go about turning it on? I can see how to tweak the numbers, but how does one actually turn on the Scanline Sync, or is it done by simply changing the number there? I don't see any difference when I'm changing the numbers, so maybe I'm doing something wrong. Thanks in advance!

User avatar
Chief Blur Buster
Site Admin
Posts: 6608
Joined: 05 Dec 2013, 15:44

Re: RTSS Scanline Sync HOWTO

Post by Chief Blur Buster » 01 Dec 2019, 15:32

MrFix wrote:
01 Dec 2019, 14:21
How does one go about turning it on? I can see how to tweak the numbers, but how does one actually turn on the Scanline Sync, or is it done by simply changing the number there? I don't see any difference when I'm changing the numbers, so maybe I'm doing something wrong. Thanks in advance!
1. Calibrate it using VSYNC OFF
2. Use horizontal panning motion (continual panning or strafing)
3. Use a game whose frame rate that rarely dip below Hz
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

ipiv
Posts: 2
Joined: 15 Jan 2020, 03:28

Re: RTSS Scanline Sync HOWTO

Post by ipiv » 15 Jan 2020, 03:31

I was trying to find the optimal way to use Scanline sync in a fps capped game (Game has fps limiter implemented and no way to uncap fps).

At the moment I have it running perfectly but I was curious whether the in-game limiter and RTSS's limiter are fighting against each-other,
since both are running in parallel?

Moreover, I was wondering if there is a way to disable RTSS's limiter, use the in-game limiter and therefore only use RTSS to apply tearline positioning?

User avatar
RealNC
Site Admin
Posts: 2863
Joined: 24 Dec 2013, 18:32
Contact:

Re: RTSS Scanline Sync HOWTO

Post by RealNC » 15 Jan 2020, 14:05

ipiv wrote:
15 Jan 2020, 03:31
At the moment I have it running perfectly but I was curious whether the in-game limiter and RTSS's limiter are fighting against each-other,
since both are running in parallel?
That's fine. They can both work at the same time. The lowest cap normally wins, but in scanline sync mode, RTSS will still cap the game just at the right moment for tearline positioning.
Moreover, I was wondering if there is a way to disable RTSS's limiter, use the in-game limiter and therefore only use RTSS to apply tearline positioning?
Scanline sync is the RTSS frame limiter. It's just a different mode of operation compared to normal FPS-based cap. In normal mode, RTSS just caps frame times to 1000/fps_cap milliseconds. In scanline sync mode, RTSS caps frame times to 1000/monitor_hz milliseconds with the exact time the frame limiter activates depending on the monitor's current scanout position.
SteamGitHubStack OverflowTwitter
The views and opinions expressed in my posts are my own and do not necessarily reflect the official policy or position of Blur Busters.

ipiv
Posts: 2
Joined: 15 Jan 2020, 03:28

Re: RTSS Scanline Sync HOWTO

Post by ipiv » 16 Jan 2020, 12:12

Thanks, @RealNC.
I see, the action (fps limiter), which controls the scanline positioning is not actually a separate functionality as I had previously thought.

Yeah, I have it currently running perfectly and coupled with strobe crosstalk for blur reduction results in super smooth gameplay with minimal input lag.
Thanks to @Chief Blur Buster for the guide!

User avatar
Chief Blur Buster
Site Admin
Posts: 6608
Joined: 05 Dec 2013, 15:44

Re: RTSS Scanline Sync HOWTO

Post by Chief Blur Buster » 16 Jan 2020, 23:38

ipiv wrote:
16 Jan 2020, 12:12
Thanks, @RealNC.
I see, the action (fps limiter), which controls the scanline positioning is not actually a separate functionality as I had previously thought.

Yeah, I have it currently running perfectly and coupled with strobe crosstalk for blur reduction results in super smooth gameplay with minimal input lag.
Thanks to @Chief Blur Buster for the guide!
You are very welcome!

Correct, scanline position is synonymous with framerate capping, since each pixel row (scanline) is scanned-out once every refresh cycle, as seen in high speed videos at www.testufo.com/scanout ...

Scanline sync cues on the exacts timing of the scanout of a single pixel row (raster based sync). It essentially guarantees fps=Hz if game engine can keep up. Which pixel row (scanline) to sync to, helps you determine tearline placement (in a perfect world, tearline location = scanline location -- but they're usually a few pixels apart due to overheads).

Fine tuning the scan line number, allows you to steer the tearline offscreen between refresh cycles (below bottom edge of current refresh / above top edge of next efresh .... when you metaphorically picture it as an endless reel of refresh cycles like the Blur Busters scanout diagrams, the "below/above" is conceptually exactly the same thing)

So in this sense, scanline sync really cannot be decoupled from framerate cap, it's really a fps=Hz cap unless you sync to 2 scanlines via custom config file edit, then it becomes fps=(2xHz) with the disadvantage of a on-screen tearline that cannot be hidden.
Head of Blur Busters - BlurBusters.com | TestUFO.com | Follow @BlurBusters on Twitter

       To support Blur Busters:
       • Official List of Best Gaming Monitors
       • List of G-SYNC Monitors
       • List of FreeSync Monitors
       • List of Ultrawide Monitors

Post Reply