Screen tearing is ugly, but the usual cure, V-Sync, adds noticeable input lag, and not everyone has a G-Sync or FreeSync monitor. RivaTuner Statistics Server (RTSS), the tool bundled with MSI Afterburner, offers a clever alternative called Scanline Sync. It steers the tear line off the visible screen instead of buffering frames, giving you tear-free image with far less latency than V-Sync. It takes a little tuning, but the payoff is excellent.
How Scanline Sync Differs From V-Sync
V-Sync forces the GPU to wait for the monitor’s refresh, which prevents tearing but queues frames and adds lag. Scanline Sync instead times the frame flip so the inevitable tear happens on a specific scanline, one you push into the top or bottom edge or vertical blanking interval where you cannot see it. You keep low latency and lose the visible tear.
What You Need
- RTSS (installs with MSI Afterburner) running in the background.
- A game running in exclusive fullscreen for best results.
- Enough GPU headroom to slightly exceed your refresh rate, then be capped.
Setting It Up
- Open RTSS and select the global or per-game profile.
- Find the “Scanline sync” field (the framerate limit box has a small dropdown to switch modes).
- Enter a value: a positive number counts scanlines from the top, a negative number from the bottom.
- Start near the top with a small positive number and adjust until the tear line sits in the blanking area and disappears.
- Disable in-game V-Sync so the two do not fight.
Tuning the Scanline Value
| Value Type | Where Tear Goes | When to Use |
|---|---|---|
| Small positive (e.g. 5-40) | Near top edge | Most common starting point |
| Large negative (e.g. -100) | Near bottom edge | If top does not hide it |
| Zero-ish / VBI | Blanking interval | Ideal, fully invisible |
The correct value depends on your resolution and game, so expect a minute of trial and error. When the tear line vanishes into the edge, you have found it. Your GPU must consistently render faster than the refresh rate for Scanline Sync to hold the line steady.
Realistic Expectations
Scanline Sync works beautifully in games where your GPU comfortably exceeds the monitor’s refresh rate. If your frame rate dips below refresh, the tear line will wander and reappear. It is therefore best for older or well-optimized titles, or paired with a frame rate ceiling. It is not a replacement for VRR if you have it, but it is a superb option for fixed-refresh panels.
Why Headroom Is the Whole Game
Scanline Sync only works when your GPU renders each frame faster than the monitor refreshes, because it needs to finish early enough to flip the buffer at a precise scanline. If your frame rate falls below the refresh rate, the timing slips and the tear line wanders back into view. This is why the technique pairs so well with older esports titles and well-optimized games where a modern GPU comfortably exceeds 144 or 240fps. For heavier games that dip below refresh, it is better to either lower settings for headroom or rely on VRR if your monitor supports it.
Half-Refresh Scanline Sync
RTSS also supports fractional Scanline Sync values that lock to half your refresh rate, useful when a game cannot sustain full-refresh frame rates but can hold, for example, a steady 72fps on a 144Hz panel. This gives you a tear-free, consistent experience at a lower but rock-solid frame rate, which many players prefer over an uneven full-rate image. Experiment with the fractional mode when full Scanline Sync will not hold; it broadens the range of games where you can enjoy a clean picture without paying V-Sync’s latency penalty.
FAQ
Does Scanline Sync add input lag like V-Sync?
Much less. Because it does not queue extra frames the way V-Sync does, latency stays close to an uncapped, tearing image while still hiding the tear. That low-lag, tear-free combination is exactly why enthusiasts favor it on non-VRR monitors.
Why does the tear line keep moving on my screen?
Your frame rate is probably dropping below the refresh rate, so the GPU cannot hold the flip timing steady. Lower a few settings to keep FPS above refresh, or use Scanline Sync only in games where you have plenty of GPU headroom.
Bottom Line
RTSS Scanline Sync is a brilliant, free way to get tear-free gaming without V-Sync’s latency, especially on monitors without G-Sync or FreeSync. Run RTSS, enter a scanline value, and tune it until the tear hides in the screen edge or blanking interval. Keep your frame rate above the refresh rate and you will enjoy a clean image with responsive controls.
