Variable refresh rate technologies like FreeSync and G-Sync eliminate screen tearing by syncing the monitor’s refresh to your game’s frame rate. But there is fine print that rarely makes the box: every adaptive-sync monitor has a range, and what happens when your frame rate drops below that range depends on a feature called Low Framerate Compensation. Understanding both explains why some VRR monitors stay smooth in demanding games and others stutter.
What the adaptive sync range is
A VRR monitor can only vary its refresh rate within a defined window, for example 48 to 144Hz or 30 to 240Hz. Inside that window, the panel matches its refresh to your frame rate one-to-one, so 90fps means 90Hz and the image is tear-free and smooth. The width of that range, and especially where its bottom sits, is a quality differentiator that cheaper monitors often skimp on with a narrow range like 48 to 75Hz.
| VRR range example | LFC possible? | Behavior below the floor |
|---|---|---|
| 48-144Hz | Yes (ceiling > 2x floor) | Frames multiplied, stays smooth |
| 40-144Hz | Yes | Smooth down to very low fps |
| 48-75Hz | No (ceiling < 2x floor) | Tearing or stutter below 48fps |
| 30-240Hz | Yes | Excellent, wide usable range |
Why the bottom of the range matters
Demanding games and higher resolutions push frame rates down, sometimes below the monitor’s minimum sync value. When your frame rate falls beneath the floor, the monitor can no longer match it directly, and without help you get the tearing or stutter that VRR was supposed to prevent. That is exactly the situation Low Framerate Compensation was designed to handle.
How Low Framerate Compensation works
Low Framerate Compensation (LFC) keeps things smooth below the sync floor by displaying frames multiple times to keep the panel refreshing within its valid range. If your game runs at 35fps but the monitor’s floor is 48Hz, LFC shows each frame twice, refreshing at 70Hz, which is inside the range, while still presenting 35 unique frames per second tear-free. The technique requires the monitor’s maximum refresh to be at least roughly double its minimum, which is why a wide range like 48 to 144Hz supports LFC and a narrow 48 to 75Hz range does not.
FreeSync and G-Sync both use it
LFC exists under both major VRR ecosystems; AMD calls it Low Framerate Compensation and NVIDIA’s G-Sync handles the same problem within its own implementation. Native G-Sync modules typically operate down to very low frame rates seamlessly, while FreeSync monitors rely on a wide enough advertised range to enable LFC. When comparing monitors, a wide range with LFC support is far more valuable than a headline maximum refresh rate alone.
What to look for when buying
Do not just read the top number. Check the full adaptive-sync range and confirm the maximum is at least about double the minimum so LFC can engage. A monitor rated 48 to 144Hz with LFC will stay smooth even when a heavy game dips into the 30s, whereas a 48 to 75Hz panel will stutter as soon as you fall below 48fps. For 4K gaming, where frame rates swing widely, a wide VRR range with working LFC is one of the most underrated features you can buy.
Frequently asked questions
How do I know if my monitor supports LFC?
Check whether the monitor’s maximum refresh rate is at least roughly twice its minimum adaptive-sync value; if so, LFC is supported. Manufacturer spec sheets and certification listings usually state the VRR range, and FreeSync Premium and Premium Pro tiers require LFC, so those badges guarantee it.
Does LFC add input lag?
LFC repeats frames to keep the panel in range, and its effect on latency is minimal in practice; you still see the same unique frames your GPU renders. The smoothness benefit of avoiding stutter and tearing below the sync floor far outweighs any negligible timing overhead.
Bottom line
Every adaptive-sync monitor has a refresh range, and Low Framerate Compensation keeps the picture smooth when your frame rate drops below that range by repeating frames to stay in the valid window. LFC needs a maximum refresh about double the minimum, so when buying a VRR monitor, prioritize a wide range with LFC support over a big headline refresh number, especially for demanding or 4K gaming.
