G-SYNC is NVIDIA’s variable refresh rate technology that makes a monitor refresh exactly when the graphics card finishes a frame, instead of on a fixed schedule. For gaming performance, it removes screen tearing and most of the stutter caused by mismatched timing, while adding far less input lag than traditional V-Sync.
G-SYNC is one implementation of the broader idea known as VRR. It began as a proprietary hardware module built into monitors and has since grown into a family of certification tiers, including G-SYNC Compatible displays that use the open VESA Adaptive-Sync standard, the same foundation used by AMD FreeSync.
How G-SYNC synchronizes the display
A conventional monitor refreshes at a fixed interval, for example every 6.94 ms at 144 Hz. A GPU rarely finishes frames at exactly that pace. If the display shows a new frame mid-scan, the screen shows parts of two frames at once, which is tearing. If the GPU waits for the next refresh instead, as V-Sync does, frames are delayed and uneven timing shows up as stutter and extra latency.
G-SYNC reverses the relationship. The display holds the vertical blanking interval until the GPU delivers a complete frame, then starts scanning it out immediately. The refresh interval therefore follows the frame time: a frame that took 9 ms is shown for 9 ms, and one that took 12 ms is shown for 12 ms, within the panel’s supported range.
When the frame rate falls below the panel’s minimum refresh rate, the system shows each frame two or more times so the panel stays within its range. AMD calls the same idea low framerate compensation. The hardware module handles this internally, which is one reason module-based displays often advertise operation down to very low frame rates.
G-SYNC tiers and certification
The G-SYNC name covers several tiers that differ in hardware, testing and feature set. Knowing the tier explains why two monitors with the same label can behave differently.
| Tier | How it is implemented | Notable characteristics |
|---|---|---|
| G-SYNC Compatible | VESA Adaptive-Sync, tested by NVIDIA | No module; validated for no blanking or flicker |
| G-SYNC | NVIDIA module or certified scaler | Full VRR range, variable overdrive, factory tuning |
| G-SYNC Ultimate | NVIDIA module or certified scaler | Adds high-brightness HDR requirements |
| G-SYNC Pulsar | Certified hardware with strobing | Combines VRR with backlight strobing for motion clarity |
The dedicated module brings variable overdrive, which adjusts pixel response tuning to the current refresh rate. Without it, overdrive tuned for maximum refresh can cause overshoot artifacts at lower frame rates. Newer certified displays move the same functions into partner monitor scalers instead of a separate board.
G-SYNC compared with FreeSync and V-Sync
G-SYNC, FreeSync and V-Sync all address the timing mismatch between GPU and display, but they make different trade-offs between tearing, latency and hardware requirements.
| Approach | Tearing | Added latency | Requirement |
|---|---|---|---|
| No synchronization | Visible | Lowest | None |
| V-Sync on a fixed refresh display | None | High, especially when buffered | None |
| G-SYNC | None inside the range | Very low | NVIDIA GPU and supported display |
| FreeSync | None inside the range | Very low | Adaptive-Sync display and supported GPU |
| HDMI 2.1 VRR | None inside the range | Very low | HDMI 2.1 VRR source and display |
Since NVIDIA added support for Adaptive-Sync displays, the practical gap has narrowed: many FreeSync monitors run VRR on NVIDIA GPUs through the G-SYNC Compatible path, even if they are not formally certified. Differences now lie mostly in range width, overdrive behavior and quality control rather than in the basic principle.
Recommended G-SYNC settings
The widely used configuration combines G-SYNC with a frame rate cap slightly below the maximum refresh rate. If the frame rate exceeds the refresh rate, the display leaves the VRR range and falls back to V-Sync behavior or tearing.
| Setting | Recommended value | Purpose |
|---|---|---|
| G-SYNC in the driver | Enabled for full screen or windowed mode | Turns on variable refresh |
| V-Sync in the driver | On | Prevents tearing when frame times spike |
| In-game V-Sync | Off | Avoids double buffering in the game |
| Frame rate cap | About 3 to 4 fps below refresh rate | Keeps output inside the VRR range |
| Low latency mode or NVIDIA Reflex | On where supported | Shortens the render queue |
With driver V-Sync on and a cap below the refresh rate, V-Sync acts only as a safety net for frame-time spikes and adds almost no latency. Games that support NVIDIA Reflex often apply a suitable cap automatically when G-SYNC and V-Sync are both active.
Limitations and common problems
G-SYNC smooths frame delivery to the screen, but it cannot fix uneven frame production. Shader compilation hitches, CPU bottlenecks and poor frame pacing still appear as stutter, because a 50 ms frame is still shown late even when the display waits for it.
- VRR flicker can appear on some OLED and VA panels when the frame rate swings widely, especially in dark scenes.
- Narrow VRR ranges on cheaper Adaptive-Sync monitors leave gaps where compensation does not work well.
- Running above the refresh rate without a cap disables the benefit and reintroduces tearing or V-Sync lag.
- Windowed mode issues occur when the driver option is set to full screen only.
In everyday language
A normal screen updates on a strict timetable, like a bus that leaves every few milliseconds whether passengers are ready or not. The graphics card finishes pictures at an uneven pace. The mismatch causes torn images or jerky motion.
G-SYNC changes the rule. The screen waits for each finished picture and shows it right away. Motion looks smooth and the controls stay responsive, even when the game speed varies from moment to moment.
Seen in the real world
A player with a 240 Hz monitor and an NVIDIA graphics card plays an open world game that runs between 70 and 110 fps depending on the area. Without synchronization, fast camera turns show clear horizontal tears. With in-game V-Sync on, the tearing disappears but aiming feels heavy.
The player enables G-SYNC and V-Sync in the driver, turns off in-game V-Sync and sets a global cap of 236 fps. In the demanding areas the display now refreshes in step with every frame, and the swings between 70 and 110 fps no longer look jerky.
Occasional hitches remain when the game streams new areas, which the player identifies as a frame-time problem in the game itself rather than a display issue. The overall result is tear-free, responsive play without lowering graphics settings.