Gaming Monitor Numbers Explained: Hz, Response Time, Ghosting and Sync

Refresh rate is how many times per second the monitor can draw a new image. At 60 Hz a new frame arrives every 16.7 ms; at 144 Hz every 6.9 ms; at 240 Hz every 4.2 ms. The jump from 60 to 144 is the single largest improvement most players ever buy, because motion becomes readable: an enemy crossing a doorway is drawn in twice as many positions, and your own turn stutters less.

The monitor only draws what the computer delivers. A 240 Hz panel fed 90 frames per second behaves like a 90 Hz one with better motion clarity. Before buying Hz, check what your machine produces in the games you play at the settings you use.

The classic mistake after buying a fast monitor is leaving Windows on 60 Hz. The refresh rate is set per display in the advanced display settings, and some monitors also need the high-speed mode enabled in their own menu. The refresh rate test on this site measures what the browser actually receives, which exposes this in seconds.

Response time is how long a pixel takes to change from one shade to another. The 1 ms on the box is almost always the best case (grey-to-grey with overdrive at maximum), not the typical transition. A panel that is slow on dark transitions smears dark objects moving across dark backgrounds, which is exactly where enemies hide.

Ghosting is the visible trail a slow transition leaves behind a moving object. Overdrive pushes the pixel harder to finish the transition sooner; too much of it overshoots and leaves a bright or inverse halo instead, called inverse ghosting or overshoot. Most monitors have two or three overdrive levels and the middle one is usually right; the motion test on this site shows both trails and halos on moving shapes so you can pick by eye.

Panel type sets the ceiling. TN panels switch fastest and look worst, IPS panels are the balanced choice, VA panels have the best contrast and the slowest dark transitions, and OLED has no transition time to speak of but its own burn-in and brightness caveats. Response time within a panel type varies far more than the marketing admits, which is why reviews with measured numbers beat spec sheets.

Tearing appears when the computer sends a new frame while the monitor is halfway through drawing the previous one; the top and bottom of the screen show different moments. VSync removes it by making the computer wait for the monitor, at the cost of input latency and stutter whenever the frame rate dips.

Adaptive sync (FreeSync, G-Sync, or the generic VESA standard) turns this around: the monitor waits for the computer and refreshes the instant a frame is ready, within its supported range. No tearing, no waiting. It needs to be enabled on both the monitor and the graphics driver, and it only works inside the monitor's range, so a frame rate cap just below the maximum refresh keeps it active.

A browser cannot switch VSync off, so a web page can only show tearing where the system already allows it. The tearing pattern on this site is a useful check that adaptive sync is actually engaged: if moving bars stay intact at high speed with the frame rate uncapped, the pipeline is working.

Dead and stuck pixels are the fault most likely to qualify for a return, and the one most likely to be missed until the return window has closed. A full-screen colour sweep on each primary colour and on black and white takes a minute and finds them; do it on delivery day.

Backlight bleed and IPS glow show on a dark screen in a dark room: bright patches in corners that do not move with the content. Some is normal on every LCD; a large uneven patch is worth a replacement request while you still can.

Finally, confirm the refresh rate in the operating system and run a motion test at the panel's native rate. A monitor that passes these three checks in the first week is a monitor you can stop thinking about, which is the entire point of buying a good one.