Why frame skipping needs a camera
A monitor can accept a higher refresh rate than it can show. Push it past that point with a custom resolution and it may still report the new rate and look fine at a glance, while quietly dropping some of the frames your computer sends. The computer, the graphics driver and this page all keep counting the frames they send, so the reading at the top shows the overclocked rate either way. The only way to see what the panel actually displays is to photograph it.
The pattern above lights one box per refresh, left to right and row by row. A photo exposed for several refreshes catches the boxes lit during the exposure as one unbroken run. If the monitor drops a frame, the box for that frame never lights, and the run has a gap.
Take the photo
- Close other apps and tabs, press Full screen under the pattern and wait for Ready, which appears once the reading is steady and the browser hasn’t missed a frame for a moment.
- Set your camera or your phone’s camera app to manual or pro mode with a shutter speed of 1/10 second. Blur Busters’ TestUFO frame skipping test uses the same photo method and recommends 1/10 second or longer.
- Hold the camera still, or rest it on something, and take the photo square to the screen.
- If the photo comes out too bright, lower the ISO or the monitor’s brightness rather than shortening the exposure.
At 1/10 second you should see about a tenth of the refresh rate in boxes: 14 at 144 Hz, 16 or 17 at 165 Hz, 24 at 240 Hz.
Read the photo
- One unbroken run: every frame arrived on screen. The rate is safe to use.
- A gap: the monitor skipped a frame. Gaps that repeat evenly mean it skips all the time at this rate.
- One brighter box: the browser missed a refresh and the same frame showed twice. That’s the computer, not the monitor; check the Dropped frames figure and photograph again.
Overclocking a monitor step by step
On NVIDIA cards, open the NVIDIA Control Panel, Display, Change resolution, then Customize and Create Custom Resolution; NVIDIA’s own help has you press Test before Save. On AMD, open AMD Software, search for Custom Resolution, choose Create New, then Create: AMD checks the settings against the display and the screen may go blank for a moment. Raise the rate a little at a time, test each step here and keep the highest rate with an unbroken run.
Before overclocking, check the rate the monitor already runs at with the 144 Hz test or the 240 Hz test, which also show how much video data each rate needs over each connection. The plain refresh rate test has the frame timing chart and motion test for any display.