Uncapped frame rates feel smooth until you look closely at the frame time graph and see the spikes. VSync eliminates tearing but adds latency. NVIDIA’s in-driver frame limiter is decent but lacks granular control. RivaTuner Statistics Server (RTSS) sits in a different tier entirely — a process-level frame limiter with sub-millisecond precision that has been the tool of choice for enthusiasts and competitive players for over a decade.
Installing RTSS with MSI Afterburner
RTSS is bundled with MSI Afterburner, which remains the most common installation path even for users who have no interest in GPU overclocking. Download the latest version from msi.com/Landing/afterburner/graphics-cards (the official Afterburner page). The installer packages both applications together.
During installation:
- Run the installer as administrator.
- Accept the Afterburner license, then accept the separate RTSS license when prompted.
- Allow both to install to their default directories (
C:\Program Files (x86)\MSI AfterburnerandC:\Program Files (x86)\RivaTuner Statistics Server). - Let RTSS launch at Windows startup — it needs to be running before games launch to hook into them.
RTSS appears as a small icon in the system tray (a red lightning bolt). Double-click it to open the main interface. Afterburner is not required to be open for RTSS frame limiting to work.
Setting a Frame Rate Limit
In the RTSS main window, the Framerate limit field at the bottom accepts any integer value. The question is what value to set.
For 60 Hz monitors: Set the limit to 58 or 59, not 60. Capping exactly at refresh rate creates a buffer race condition where frames occasionally miss the VSync window and introduce stutter. One to two frames below refresh provides headroom without noticeable visual difference.
For 144 Hz monitors: Common recommendations are 141 or 142. If you are running DLSS or FSR and consistently hitting the cap, 138–140 gives the GPU more breathing room before it starts queuing frames.
For variable refresh rate (G-Sync/FreeSync): Set the limit to 3–4 FPS below the monitor’s maximum refresh rate. This keeps you inside the VRR window, avoiding the fallback to fixed VSync that activates above the monitor’s rated maximum.
For competitive play with a VRR monitor disabled: Many players disable VRR entirely and set a frame cap well above the refresh rate (e.g., 300 FPS cap on a 240 Hz monitor) to minimize latency while accepting tearing. RTSS handles this cleanly.
Scanline Sync: Advanced Frame Pacing
Scanline Sync is RTSS’s signature feature and the reason many advanced users prefer it over standard VSync. Instead of synchronizing frame delivery to the vertical blank interval (which adds half a frame of latency on average), Scanline Sync synchronizes the frame delivery to a specific horizontal scanline position as the monitor draws.
To enable it:
- Open RTSS.
- In the Scanline sync field, enter a negative value like -1. This tells RTSS to present each frame just as the monitor finishes drawing the previous one.
- For fine-tuning, adjust toward more negative values (e.g., -4, -8) if you notice a small tear line near the top of the screen.
The tear line will be pushed off-screen entirely when tuned correctly. The result is tearing-free output with significantly lower latency than traditional VSync — often approaching the latency of a fully uncapped, tearing frame rate.
Scanline Sync is only effective when your frame rate is at or slightly above the monitor refresh rate. If your GPU cannot maintain that, it falls back to tearing. For this reason, Scanline Sync works best combined with a frame cap set to refresh rate + 2 to 5 FPS.
Input Lag: RTSS vs VSync
Understanding why RTSS reduces input lag compared to driver-level VSync requires understanding the render pipeline:
| Method | Frame Buffer | Latency Profile |
|---|---|---|
| No cap, no VSync | Immediate present | Lowest latency, heavy tearing |
| Driver VSync | Double/triple buffer | +8–17 ms (one full frame at 60 Hz) |
| RTSS frame cap, no VSync | No buffer queuing | Near-uncapped latency, no tearing if scanline synced |
| NVIDIA Reflex (DX12) | Engine-level sync | Similar to RTSS, game-dependent |
RTSS works at the driver hook level, inserting a precise sleep between frames before the GPU present call. This prevents the GPU command queue from filling up — a filled queue is the primary source of “GPU-induced” input latency even when average FPS looks fine.
In practice, on a 144 Hz monitor with RTSS capped at 141 and Scanline Sync enabled at -1, measured click-to-pixel latency is typically within 2–4 ms of fully uncapped output, with no tearing.
Overlay Configuration
RTSS provides the overlay engine used by Afterburner’s in-game display. To configure it:
- Open MSI Afterburner and click the settings gear icon.
- Go to the Monitoring tab. Check the boxes next to the metrics you want displayed: GPU usage, GPU temperature, VRAM usage, framerate, and frametime are the most useful.
- For each metric, check Show in On-Screen Display.
- In the On-Screen Display tab, set your preferred hotkey to toggle the overlay (default is Scroll Lock).
- In RTSS itself, under On-Screen Display, adjust the font size and position. RTSS uses a monospace bitmap font by default; importing a custom font (via the Plugins\OSDRT directory) gives you the smoother vector-rendered overlay.
For competitive use, disable the overlay entirely — even lightweight overlays have a small CPU cost and can affect 0.1% lows in CPU-bound scenarios. Enable it for benchmarking and diagnostics, then turn it off for actual play.
RTSS is one of the few third-party tools that genuinely improves both frame pacing and input latency when configured correctly. The ten minutes spent setting it up pay off every session.