Why is my 240Hz monitor only showing 144Hz?
Updated 2026-09-03
Your monitor is rated 240Hz, but Windows only offers 144Hz (or 120Hz) in the display settings. In almost every case this is a link-bandwidth or connection problem, not a broken monitor. The signal for the full rate doesn't fit down the cable you're using, so the highest mode the two devices can agree on is lower.
The short answer
Use the connector the monitor's high refresh rate is actually rated for (usually DisplayPort), make sure DSC is allowed if the mode needs it, and check that colour depth / HDR isn't pushing the mode past the link's limit. Then re-select the refresh rate in your OS.
Why it happens
- Wrong port. Many monitors reach their top refresh rate only on DisplayPort. The HDMI port may be an older version (HDMI 2.0 tops out around 1440p 120-144Hz or 4K 60Hz).
- Not enough uncompressed bandwidth. DisplayPort 1.4 carries about 25.9 Gbps of usable data. 1440p 240Hz or 4K 144Hz at 8-bit is close to or beyond that, so the mode needs Display Stream Compression (DSC).
- DSC disabled or unsupported. If DSC isn't active - old GPU, disabled in settings, or a cable/adapter that breaks it - the high mode disappears from the list.
- 10-bit or HDR raises the requirement. Going from 8-bit to 10-bit adds roughly 25% to the bandwidth needed, which can tip a mode over the edge.
- Cable. A cable not rated for the bandwidth (especially cheap or long HDMI, or a passive DP-to-HDMI adapter) will silently fall back.
- OS / driver setting. Windows sometimes keeps a previously selected lower rate; the NVIDIA/AMD control panel may need the mode set explicitly.
Check it in order
- Confirm which port your cable is in, and which port the monitor's spec sheet lists for the top refresh rate. Move the cable to that port.
- Use a certified cable rated for the bandwidth (DisplayPort 1.4 / DP80, or Ultra High Speed HDMI for HDMI 2.1).
- In the NVIDIA Control Panel (Change resolution) or AMD Software (Display), set the refresh rate and colour settings explicitly.
- If the mode needs DSC, make sure your GPU supports it (NVIDIA RTX 20-series or newer; recent AMD Radeon) and that any adapter in the chain is DSC-capable.
- Try 8-bit / SDR first. If the full rate appears at 8-bit but not 10-bit, the link is the limit.
- Run a check for your exact GPU and monitor to see which connector reaches your target and whether DSC is required.