What Is Screen Tearing?

Screen tearing is a visible horizontal split in the image that appears when the graphics card’s frame rate and the monitor’s refresh rate are out of sync, so the display shows parts of two different frames at once. The split occurs because the monitor begins drawing a new frame from the graphics card before it finishes displaying the previous one, placing the upper and lower portions of the screen on separate frames. This article defines screen tearing, explains why it happens when a frame is delivered mid-refresh, and describes the solutions: V-Sync that holds frames to the refresh cycle, adaptive sync technologies G-Sync and FreeSync that vary the refresh rate to match the frame rate, and frame-rate caps that reduce the mismatch.

The article also covers the input-lag drawback of standard V-Sync. Screen tearing is a synchronization artifact, not a hardware fault, and each solution addresses the timing mismatch between rendering and display in a different way. Each section answers one question about the cause and the available fixes.

What Is Screen Tearing?

Screen tearing is a visible horizontal split in the image, caused when the graphics card delivers a new frame while the monitor is still drawing the previous one, so the screen shows two frames at the same time. The display draws each frame from top to bottom, and when a fresh frame arrives partway through that process, the top of the screen shows the new frame while the bottom still shows the old one, creating a torn line. Screen tearing has three defining traits:

• The horizontal split appears as a misaligned line where the upper and lower portions of the screen show different frames.
• The mid-refresh delivery causes the split, since a frame arriving during a redraw replaces only part of the displayed image.
• The motion dependence makes tearing most visible during fast horizontal movement, such as turning the camera or panning.

Screen tearing arises from a mismatch between frame rate and refresh rate, the two values defined in the explanation of FPS in gaming and the explanation of monitor refresh rate. The artifact is a timing issue between rendering and display, not a fault in the graphics card or monitor.

Why Does Screen Tearing Happen?

Screen tearing happens because the graphics card and the monitor run on independent timing, so a frame can be sent to the display in the middle of a refresh cycle, splitting the screen between two frames. The monitor refreshes at a fixed rate, while the graphics card renders frames at a variable rate that rarely lines up with the refresh.

When a new frame arrives mid-refresh, the display writes it over the portion not yet drawn. The cause works as follows:

• Independent timing means the graphics card outputs frames whenever they finish, without waiting for the monitor’s refresh cycle.
• The frame-rate and refresh-rate mismatch ensures frames arrive at points that do not align with the start of a refresh.
• The mid-refresh overwrite places the new frame on the lower part of the screen while the upper part still shows the previous frame.

Tearing is most visible when the frame rate is far from a multiple of the refresh rate, since the split line then moves and appears more often. The mismatch that produces tearing also relates to the latency between rendering and display, covered in the explanation of input lag in gaming.

How Does V-Sync Fix Screen Tearing?

V-Sync fixes screen tearing by forcing the graphics card to hold each finished frame until the monitor is ready for it, aligning frame delivery with the start of each refresh cycle so no frame arrives mid-refresh. Vertical synchronization caps the frame rate at the refresh rate and synchronizes the two, removing the split. V-Sync works as follows:

• The frame hold keeps a finished frame in a buffer until the monitor begins a new refresh, preventing a mid-refresh overwrite.
• The frame-rate cap limits output to the refresh rate, since the graphics card waits for the display rather than running ahead.
• The buffer use stores one or more frames so the next refresh starts with a complete image, removing the torn line.

V-Sync removes tearing but introduces a drawback in added input lag, covered in the next section, and it can cause stutter when the frame rate falls below the refresh rate. The trade-off between tear-free output and latency is examined in the explanation of input lag in gaming, with adaptive sync offering a lower-latency alternative.

How Do G-Sync and FreeSync Fix Screen Tearing?

G-Sync and FreeSync fix screen tearing by varying the monitor’s refresh rate to match the graphics card’s frame rate in real time, so each frame is displayed as soon as it is ready without the input lag of standard V-Sync. Adaptive sync technologies make the display refresh on the graphics card’s schedule rather than a fixed one, eliminating the mismatch that causes tearing. Adaptive sync works as follows:

• The variable refresh rate adjusts the monitor’s redraw timing to match each frame as it arrives, removing the mid-refresh split.
• Nvidia G-Sync uses a hardware module or the VESA Adaptive-Sync standard to synchronize the display to the graphics card.
• AMD FreeSync uses the VESA Adaptive-Sync standard over DisplayPort or HDMI to vary the refresh rate without a proprietary module.

Adaptive sync removes tearing while keeping latency far lower than V-Sync, which makes it the preferred solution on a monitor that supports it. The differences between Nvidia and AMD adaptive sync, including hardware needs and tiers, are compared in the comparison of G-Sync and FreeSync, and the monitor features that enable it appear in the gaming monitor specs explained.

What Is the Input-Lag Drawback of V-Sync?

The input-lag drawback of V-Sync is the added delay between a player’s input and the on-screen result, caused by the buffered frames V-Sync holds back to align with the refresh cycle. Holding frames in a buffer until the monitor is ready adds time between when a frame is rendered and when it appears, which raises input lag. The drawback works as follows:

• The buffered delay adds latency because a finished frame waits for the next refresh instead of displaying immediately.
• The double-buffer stutter halves the frame rate when output falls below the refresh rate, dropping from 60 to 30 on a 60-hertz panel.
• The competitive cost matters most in fast games, where added latency slows the response between aim and on-screen movement.

A frame-rate cap set just below the refresh rate reduces tearing with less latency than V-Sync, and adaptive sync removes the drawback by displaying frames as they arrive. The latency added by V-Sync and the methods to lower it appear in the guide to reducing input lag, while the adaptive-sync alternative is detailed in the comparison of G-Sync and FreeSync.

How Do You Detect Screen Tearing?

Screen tearing is detected by watching for a horizontal split line during fast horizontal motion, which appears as a misaligned seam where the top and bottom of the screen show different frames. The artifact is easiest to see when the camera pans quickly, since the split between two frames is most visible against moving content. Tearing is identified by three signs:

• The moving seam appears as a horizontal line that shifts position during fast camera movement, marking the boundary between two frames.
• The split during panning shows most clearly when turning quickly or scrolling, where the frame difference is largest.
• The absence with adaptive sync confirms the cause, since enabling G-Sync or FreeSync removes the seam if tearing was present.

A test pattern that pans a vertical line across the screen makes tearing obvious, since the line breaks at the split. Tearing that appears only without synchronization confirms a timing mismatch rather than a panel fault, resolved by the adaptive sync compared in the comparison of G-Sync and FreeSync.

What Is the Difference Between Tearing and Stutter?

Screen tearing is a horizontal split from a frame delivered mid-refresh, while stutter is an uneven gap between frames that makes motion jerk, so tearing is a synchronization artifact and stutter is a frame-timing problem. The two look different on screen and arise from different causes, though both reduce perceived smoothness. Tearing and stutter differ in three ways:

• The appearance differs because tearing shows a split line while stutter shows a brief freeze or jerk in motion.
• The cause differs because tearing comes from a frame-to-refresh mismatch while stutter comes from uneven frame delivery or a dropped frame.
• The fix differs because adaptive sync removes tearing while steadier frame times, often from a hardware or driver change, reduce stutter.

Stutter from uneven frame times traces to causes such as a CPU bottleneck or background load, examined in the explanation of what causes FPS drops, while tearing is a pure timing artifact removed by synchronization. The frame-timing consistency behind stutter relates to the one-percent lows defined in the explanation of FPS in gaming.

Key Takeaways

• Screen tearing is a horizontal split caused when a new frame arrives while the monitor is still drawing the previous one.
• It happens from independent timing, since the graphics card and monitor run on separate schedules that rarely align.
• V-Sync fixes tearing by holding frames to the refresh cycle, but it adds input lag and can cause stutter.
• G-Sync and FreeSync fix tearing by varying the refresh rate to match the frame rate with far lower latency.
• A frame-rate cap reduces tearing with less latency than V-Sync when adaptive sync is unavailable.
• Adaptive sync is the preferred solution on a monitor that supports it, removing tearing without the V-Sync drawback.

Last Thoughts on Screen Tearing

Screen tearing is a horizontal split caused when the graphics card delivers a frame mid-refresh, a timing mismatch between rendering and display rather than a hardware fault. V-Sync fixes it by holding frames to the refresh cycle at the cost of input lag, while G-Sync and FreeSync vary the refresh rate to remove tearing with far lower latency, and a frame-rate cap offers a partial fix. Readers can continue with the comparison of G-Sync and FreeSync, the explanation of monitor refresh rate, the explanation of input lag in gaming, or the PC gaming guide hub for related concepts.