Monitor flickers at 60Hz but not 144Hz – fix

Quick answer

Try using a DisplayPort cable rated for your monitor's max resolution and refresh rate. If you're on HDMI, swap to DisplayPort. Also disable GPU scaling in your graphics driver and test each refresh rate one by one through Windows display settings.

Why this happens

This flicker at lower refresh rates—especially 60Hz—is more common than you'd think. I've seen it on gaming monitors from Asus, Dell, and LG, and it pops up most often when you plug a high-refresh monitor into a laptop or desktop that's also driving a secondary 60Hz display. The root cause is almost always a cable bandwidth mismatch or a GPU scaling setting that doesn't play nice with the monitor's scaler.

Here's what's going on: modern high-refresh monitors (144Hz, 165Hz, 240Hz) use a scaler chip that's optimized for higher refresh rates. When you drop down to 60Hz—say because you're running a second monitor at 60Hz or you set the refresh rate lower for battery saving—the scaler has to change its timing. If the cable (especially an older HDMI cable) doesn't have enough bandwidth to carry the full resolution at 60Hz with the monitor's preferred color depth, the signal gets noisy. That noise shows up as flicker, stutter, or even black flashes.

Another major culprit: GPU scaling. When your graphics card handles the scaling instead of the monitor, it can introduce timing issues at non-native refresh rates. This is especially common on Nvidia cards where the default scaling mode is set to GPU.

Step-by-step fix

1. Check your cable. If you're using an HDMI cable, especially one that came with the monitor or is older than HDMI 2.0, swap it out for a DisplayPort cable. DisplayPort handles variable refresh rates more consistently. After you swap, reboot the monitor (turn it off for 30 seconds, then back on). You should see the flicker disappear at 60Hz immediately.
2. Disable GPU scaling. Open your graphics control panel. For Nvidia users: right-click desktop, open Nvidia Control Panel, go to Display -> Adjust desktop size and position. Set scaling mode to 'No scaling' (or 'Aspect ratio' if you need scaling, but 'No scaling' is safest). Check the box 'Override the scaling mode set by games and programs'. Click Apply. The screen will flash—that's normal. After that, test 60Hz again.
3. Force a clean refresh rate switch. Open Windows Display settings (right-click desktop -> Display settings -> Advanced display). Under 'Choose a refresh rate', pick 60Hz. Wait 10 seconds. If it flickers, switch to 120Hz, then back to 60Hz. This resets the monitor's internal timing. I've seen this fix the issue on Dell S2721DGF monitors more than once.
4. Check monitor OSD settings. Press the monitor's menu button. Look for a setting called 'DisplayPort version' or 'HDMI version'. Set it to the highest version your cable supports (1.4 or 2.0). Also check for 'FreeSync Premium' or 'G-Sync Compatible' and turn it off temporarily. Some monitors have a bug where FreeSync causes flicker at low refresh rates.
5. Update your graphics driver. Download the latest driver from Nvidia or AMD, but use a clean install (the option 'Perform a clean installation' in Nvidia's installer). Old drivers can have timing bugs that only show at specific refresh rates.

Alternative fixes if the main one fails

• Change color depth. In Nvidia Control Panel -> Change resolution, set the output color depth to 8-bit (not 10-bit). 10-bit requires more bandwidth and can cause flicker at 60Hz on HDMI cables.
• Disable secondary monitors. If you're running multiple monitors, unplug all except the flickering one and test 60Hz. If the flicker stops, the issue is your secondary monitor's refresh rate conflicting. Set the secondary to the same 60Hz or use a separate GPU output.
• Try a different power outlet. It sounds wild, but I've had a case where a monitor plugged into a power strip with other high-draw devices flickered at 60Hz because of voltage drop. Plug the monitor directly into a wall outlet and retest.
• Factory reset the monitor. In the OSD menu, find 'Factory Reset' or 'Reset All Settings'. This clears any scaler timing bugs that accumulated from switching between different inputs and resolutions.

Prevention tip

Always use the cable that came with your monitor, or buy a certified DisplayPort cable (VESA-certified, not the cheap $5 ones). If you plan to run multiple monitors, set them all to the same refresh rate in Windows—mixing 60Hz and 144Hz is possible but often causes flicker on the lower-rate screen. Also, keep your monitor's firmware updated. Manufacturers like LG and Asus release firmware updates that fix scaler bugs. Check their support page every few months.