FPS, Hz, VRR and game mode: a simple guide to your games' picture

Console boxes, monitor spec sheets, game settings: everywhere you see acronyms like FPS, Hz, VRR and ALLM. They look like expert stuff, but understanding the basics helps you get the most out of the screen you already have and avoid wasting money on a new one.

This guide explains each term in simple language, based on the sources listed at the end, and finishes with a list of practical settings to check today.

FPS and Hz are not the same thing

FPS, or frames per second, is how many images your console or computer can produce each second. That number depends on the device and on how demanding the game is. Hz, the refresh rate, is a property of the screen: how many times per second it updates. A 120 Hz screen updates 120 times per second.

Having a 120 Hz screen does not make a game run at 120 frames. If the game delivers 60 frames per second, the 120 Hz screen simply shows each frame twice. The opposite also holds: if the device produces more frames than the screen can show, the extra frames just do not appear.

Think of it this way: FPS is what the device delivers, Hz is what the screen can show. The picture is only as smooth as the lower of the two.

Why the picture tears or stutters

When the game's frames and the screen's refreshes fall out of step, two well-known problems appear. The first is tearing: the screen shows pieces of different frames at once, and a line cuts across the picture. The second is stutter, when the frame count drops and the picture seems to hitch.

VRR: a screen that keeps up with the game

Variable refresh rate, or VRR, solves exactly that mismatch. With it, the screen changes its own refresh rate to follow the frames the console or computer is sending. If the game drops from 60 to 50 frames, the screen follows, and tearing and stutter are reduced. On computers, the best-known versions are NVIDIA's G-Sync and AMD's FreeSync. On TVs, VRR comes through the HDMI connection.

Game mode and ALLM: less input delay

Another important concept is input lag: the time between the console sending the picture and it showing up on screen. Many TVs do a lot of processing to make movies look better, and that adds delay. Game mode turns much of that processing off.

The difference can be huge. In a test cited by TechRadar, an LG C1 TV had about 90 milliseconds of delay outside game mode and about 5 milliseconds with game mode on, at 120 Hz. That is the difference between a command that feels instant and one that feels late.

ALLM, auto low latency mode, makes that switch on its own: the console tells the TV a game has started, and the TV switches to game mode without you opening the menu. ALLM can exist even on TVs without VRR.

A few numbers to keep in mind

• At 60 Hz, the screen shows a new frame every 16.67 milliseconds.
• At 120 Hz, every 8.33 milliseconds.
• Movies and series are usually shot at 24 or 30 frames per second, so a 120 Hz screen repeats frames in those cases.
• To enjoy 4K at 120 Hz with VRR and ALLM on current consoles, the sources recommend a TV with at least one compatible HDMI 2.1 port.

Practical settings to check today

• Turn on your TV's game mode, or check that ALLM is enabled in the TV and console settings.
• Check the TV manual for which HDMI ports accept 120 Hz, VRR and ALLM, and plug the console into them.
• Use the HDMI cable that came with the console, made for what it sends.
• In the console's video settings, look for the 120 Hz and VRR options and see whether they are on.
• Inside games, see whether there are options that favor frames per second or picture detail and try both.
• On a computer, check in the graphics card panel whether G-Sync or FreeSync is active, when the monitor supports it, and whether the selected refresh rate is the highest the monitor accepts.
• Do not spend before testing. Sometimes the screen you already own supports more than it is set to.

Is it worth changing screens?

For people who play competitive matches and have a device that can sustain high frame rates, a high refresh rate screen with VRR makes a noticeable difference. For casual players, the change may be smaller than the marketing suggests. The first step is always the same: turn on game mode, check the port and cable and enjoy what your screen already offers.