What Is FreeSync Brightness Flickering And Can You Fix It?

On some high refresh rate monitors (mostly VA), FreeSync can sometimes cause brightness flickering with FPS fluctuations. It's possible to reduce or fix it.

So, you just got a gaming monitor with a variable refresh rate technology and paired it with a compatible graphics card only to find that enabling FreeSync/G-SYNC Compatible causes horrendous brightness flickering?

Don’t give up just yet because there are a few things you can try to prevent or at least reduce the flickering.

FreeSync brightness flickering is most common on high refresh rate VA panels developed by Samsung, but it can also affect displays based on other panel technologies such as IPS and TN, though it’s rare.

This issue will not necessarily be present in every game. In some games, you might get unbearable brightness flickering; In others, it might work flawlessly – and in some, it might only occur in loading screens or in-game menus.

Also, keep in mind that one unit of a certain monitor may have this issue, but another unit of the same monitor may work perfectly fine!

It’s a bit of a mystery what’s behind all this, and there hasn’t been any official response by AMD/NVIDIA, but we do know that some units of monitors are simply more prone to having this issue.

Note that Samsung addressed and fixed this issue by adding a ‘VRR Control’ option via a firmware update to their Odyssey G7 monitors.

If you do have brightness flickering on your monitor, the only way to fix it completely is via the manufacturer’s firmware update, if it exists.

So, why does it happen, and what can you do to prevent it – if there’s no firmware fix?

Reducing Brightness Flickering With AMD Cards

amd freesync logo

Let’s say you have a 144Hz VA gaming monitor with brightness flickering in some of your games.

There are two main reasons you get brightness flickering: LFC and frequent FPS fluctuation.

If your gaming monitor has a variable refresh rate range of 48-144Hz, it will trigger LFC (Low Framerate Compensation) once your FPS (Frames Per Second) hits 47FPS or less if you have an AMD graphics card.

LFC multiplies your framerate in order to eliminate tearing even when your FPS dips below the monitor’s VRR range. For instance, at 47FPS, it gets tripled to 141Hz.

So, let’s say one second you have 48FPS, and therefore, 48Hz, and then, the next second, your FPS drops to 47FPS, and your refresh rate spikes up to 141Hz.

Because your monitor is brighter at higher refresh rates, brightness oscillates.

If your FPS is constantly around 48FPS, LFC rapidly goes on and off – thus causing brightness flickering.

A simple solution to this is to decrease your picture settings in order to maintain a higher frame rate.

Alternatively, you can use CRU (Custom Resolution Utility) to increase the VRR range.

We have a simple guide on how to use CRU.

Just like it’s the case with overclocking, increasing the VRR range will vary across different units of monitors.

So, you might be able to increase the VRR range to 30-144Hz on one monitor while another unit of the same monitor might not even go to 47-144Hz.

In the latter case, you can try decreasing the range instead so that LFC doesn’t get triggered – or you can disable LFC completely by decreasing the range to 73-144Hz.

LFC with AMD cards only works if the lower end of the VRR range is at least 2x the maximum refresh rate. For instance, 30-60Hz VRR range means that LFC works, but with 31-60Hz, there’s no LFC support.

By disabling LFC, you’ll have to rely on VSYNC to get rid of screen tearing at lower frame rates, but you can still enjoy FreeSync at higher frame rates with no issues.

On some monitors, the refresh rate might randomly jump to the maximum value (144Hz, for instance), which can cause brightness flickering too. In this case, you can try limiting the VRR range to one below the maximum (48-143Hz).

FreeSync brightness flickering can also occur with FPS fluctuations even if it’s not near the LFC threshold. This mainly happens in poorly optimized games where your FPS is all over the place.

The only way to reduce brightness flickering here is to limit the FPS in that game to whatever framerate you can maintain constantly.

Reducing Brightness Flickering With NVIDIA Cards

nvidia g sync logo

When using FreeSync with a compatible NVIDIA graphics card via the G-SYNC Compatible mode, LFC behaves a bit differently than it does with AMD cards.

LFC gets triggered regardless of the monitor’s FreeSync range.

So, if your monitor has a 120-144Hz VRR range, and you’re getting 60FPS, the monitor’s refresh rate will change to 120Hz, whereas with AMD cards – LFC wouldn’t work, and you’d get fixed 144Hz (or 60Hz if VSYNC is enabled).

Further, the LFC threshold is usually different when using an NVIDIA GPU. For instance, with many 48-144Hz FreeSync monitors, LFC kicks in at around 60FPS with NVIDIA cards!

Due to this, FPS fluctuations around the LFC threshold will cause the monitor to rapidly go up and down with refresh rates thus causing brightness flickering.

Here’s what you can do:

If you have a 144Hz monitor with a 48-144Hz VRR range, you can use CRU to decrease the range to 90-144Hz.

Because there’s no big difference in brightness at 90Hz and 144Hz, the flickering won’t be noticeable – or it will be significantly less visible. So, between 90 and 144FPS, you’ll get smooth VRR performance.

In more demanding games, you’ll need to cap your FPS to 72 or lower (to prevent the FPS  from going over 72).

Below 72FPS, LFC will double (45 – 72FPS) or triple (30 – 48FPS) the frame rate into the 90-144Hz VRR range to prevent tearing – again without as noticeable jumps in brightness.

However, this means that between 72 and 90FPS, you won’t get variable refresh rate, but depending on the game and your FPS, you can experiment with wider VRR ranges such as 80-144Hz.

If the game you’re playing doesn’t have an FPS tracker or FPS limiter in its settings, we recommend using RTSS.

Thanks to /u/frostygrin for sharing this method of preventing FreeSync brightness flickering with NVIDIA GPUs.

Reduced Refresh Rate Method

If your frame rate is mostly around 60FPS in a certain game and you have a high refresh rate gaming display, consider lowering the monitor’s refresh rate to 60Hz in order to avoid brightness flickering.

This can also help with other issues mostly associated with games locked to 60FPS.

When you lower the monitor’s refresh rate, make sure you also select the appropriate pixel response time overdrive setting.

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Rob Shafer
Rob Shafer

Rob is a software engineer with a Bachelor’s degree from the University of Denver. He now works full-time managing DisplayNinja while coding his own projects on the side.