Why is my monitor not running at its full refresh rate?

A monitor advertised at 144Hz will show a perfectly good picture at 60Hz and give you no indication that anything is wrong. Nothing warns you. The screen does not complain, the computer reports success, and the only symptom is that the smoothness you paid for is missing — which is difficult to notice if you have never seen it working. That is why this is one of the most common quietly unresolved complaints in consumer computing. The chain from computer to screen has four links, each of which can silently cap the rate, and they need checking in a specific order because three of them are invisible from the settings screen.

Step by step

1. Understand what refresh rate is, so you know what you are looking for.It is how many times per second the screen is redrawn, measured in hertz. Sixty means sixty complete new images a second; 144 means 144. The difference shows in motion — dragging a window, scrolling a page, panning in a game — and not at all in a still image. If you are trying to judge whether it is working, move a window around rather than looking at a photograph.
2. Set it in the operating system first, because it is free and it is often the whole answer.Both Windows and macOS have a display settings page with a refresh rate control, usually behind an advanced or scaling section, and it is set per screen. If a higher rate is listed and not selected, select it. Systems very often default to the lowest common rate and never revisit the decision, particularly after a driver update or a change of cable.
3. Check the monitor's own menu, which is a separate machine with its own settings.A surprising number of monitors are shipped with their highest refresh mode disabled, or with a port set to a compatibility mode that limits it. Look through the buttons on the monitor itself for anything named after the port — a DisplayPort version setting, an HDMI mode, an enhanced or ultra input setting — and for an overdrive or performance mode. If the operating system does not offer the high rate at all, this is the second place to look after the cable.
4. Work out what your connection can actually carry.This is the real cause most of the time. A given resolution at a given refresh rate needs a certain amount of bandwidth, and the connection has a fixed ceiling set by the lowest-specified thing in the chain: the port on the computer, the cable, and the port on the monitor. Exceed it and the high rate is simply not offered. A cable that works perfectly at 60Hz can be entirely incapable of the same resolution at 144Hz.
5. Prefer DisplayPort where both ends have it.For a desktop computer driving a high-refresh monitor, DisplayPort is the path of least resistance and it is usually the connection the monitor's own documentation recommends. Where only HDMI is available, the HDMI version at both ends matters — the specifications define what each version can carry, and the manufacturer's stated maximum for your specific model is the figure to trust rather than any general claim.
6. Swap the cable before you buy anything.Use the cable that came with the monitor, since it was chosen for that monitor's maximum. If it has been lost, treat an unlabelled cable from a drawer as suspect: cables are not interchangeable above ordinary resolutions and a great many sold as generic are built to an older specification. This one substitution resolves a large share of cases and costs nothing to try.
7. Check the port on the computer, not just the cable.On a desktop with a separate graphics card, plug into the card rather than the sockets on the motherboard, which are a common and invisible mistake. On a laptop, the built-in port and any USB-C or dock path may have different limits, and going through a dock or an adapter frequently costs you the top rate. Try connecting directly before blaming anything else.
8. Deal with the laptop-specific reasons separately.Laptops routinely reduce their own screen's refresh rate on battery to save power, and some drop it whenever a power-saving mode is active. If your laptop's built-in screen is smooth on mains and not on battery, that is a deliberate feature rather than a fault, and it is a setting in the power or display options.
9. Check variable refresh rate last.Adaptive sync, marketed as FreeSync or G-Sync, lets the screen vary its rate to match what the computer is producing. It is generally worth having, but a mismatched or partly supported implementation occasionally causes a screen to sit at a fixed low rate. If everything else checks out, turn it off in both the monitor menu and the graphics settings, set a fixed refresh rate, then decide whether to turn it back on.
10. Verify it, rather than assuming the setting took effect.The number in the settings box is what was requested. Confirm it is being delivered by looking at the monitor's own information display, which most monitors show in their menu and which reports the signal actually being received. That is the only reading that comes from the screen rather than from the computer.

Common mistakes

• Assuming the monitor picks its own best mode — It does not. The computer chooses, and both operating systems have historically defaulted to a conservative rate. Buying a high-refresh screen and never opening the display settings is the single commonest reason for never seeing it work.
• Reusing an old cable from a drawer — Cables are built to specifications with real bandwidth limits, and above ordinary resolutions those limits bite. An old cable that works perfectly for a 60Hz picture may be physically incapable of carrying the same picture at a high rate.
• Plugging into the motherboard on a desktop with a graphics card — It usually works, which is what makes it hard to spot, and it routes the picture through the far less capable built-in graphics. Every display should be plugged into the card.
• Turning the resolution down to get a higher rate and leaving it there — Useful as a diagnostic — it confirms a bandwidth ceiling — and a bad permanent state, because a screen not running at its native resolution can never look sharp. Fix the connection instead.

If it doesn't work

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