Manufacturers of HDTVs and computer displays aren’t shy about touting their products’ size, resolution, and contrast ratio, but input lag—the time it takes for a monitor to catch up to your keyboard, mouse, or gamepad—is rarely mentioned.
How to find and fix input lag
Because the screen needs time to process the image to increase its quality, input lag is typical in flat-screen LCD and plasma displays. The lag is barely noticeable if you use your display or HDTV for general work, browsing the Web, or watching TV or movies; any lag is more likely to be caused by utilizing a wireless keyboard and mouse and wireless Internet.
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When you use your display for anything that needs precise timing (such as video, music, or gaming), you should consider evaluating your system for input latency.
Measured Input Lag
You can measure input lag in a variety of ways. Splitting the signal between a legless CRT and an LCD is one approach. You can also utilize a Web-based reaction test, such as this one at HumanBenchmark.com, to see how you react to changing colors.
If you detect a considerable discrepancy (30ms or more) in the results on different setups, one of them is most likely lagging.
The longer-than-usual delay between pushing a button and its corresponding action on-screen makes completing intricate movements or combos more challenging for gamers. It has a significant impact on first-person shooters, fighting games, and rhythm games like Rock Band and Guitar Hero.
Reduce The Lag
Of course, some people remain stuck with a laggy display due to a lack of desire (or funds) to upgrade. Because all flat-screen displays have some lag, your objective should be to reduce it until you no longer perceive it.
First, determine whether your TV has a Game Mode, which is essentially a display establishing that disables postprocessing routines in exchange for a bit of drop in image quality.
Some manufacturers include an Overdrive setting that may increase input lag, so you’ll have to dig through the manual to discover what it does.
After that, disable as many extra video-processing features as possible. Various acronyms, such as DRE or 3DNR, are used by many manufacturers to designate their features; try turning them off to see if your lag improves.
If you’re linking your setup to your display via HDMI or component connections, consider switching to VGA. The postprocessing features on certain displays are limited to HDMI or component video inputs, leaving the VGA input unaffected.
You could use an HDfury if your device doesn’t have a proprietary VGA connection. However, we haven’t tested it yet.
Finally, certain apps and games have latency calibration settings built-in. Lag calibration functions are available as menu options in Rock Band and Guitar Hero, for example, to let you alter the game’s timing and reduce lag.
If the calibration of the games is incorrect, it might create input lag, so double-check the settings before playing that fret-melting tune.
Dig Before You Buy
In the end, there’s only so much you can do to eliminate display input lag. If you’re looking for a new HDTV or monitor, doing your research is the best way to go.
Because manufacturers don’t specify input lag measures, look for the model numbers and product names of the displays you’re interested in online. Then Google “[model name] input lag” to discover whether it’s one of the more problematic types because no one is more nitpicky about input lag than fighting game enthusiasts.
Note that while “response time” is measured in milliseconds, it is not the same as “input lag.” Greater response times can indicate that pictures will “ghost” or leave artifacts on the screen; higher response times can mean that images will “ghost” or leave artifacts.
Many manufacturers have begun to use “overdrive” display settings to reduce this phenomenon; nevertheless, these modes might increase input lag. You’ll still want a display with fast response times, but not because of input lag.
Consumer-oriented “twisted nematic” (TN) LCD panels have the fewest input lag issues. Therefore photo-professional-grade LCDs might not be suitable for you. Digital signage—displays marketed to hospitals, airlines, and other entities—is another source of low-lag displays.
These displays frequently employ the same panels as HDTVs but without postprocessing. However, taking your laptop or gaming console with you and asking the sales reps whether you can check the screen’s function is the best and easiest method to conduct your research.
If you want to buy your monitor online, seek a retailer with the model you desire and request a test. (Better yet, bring a printout of the online advertised price and see if the brick-and-mortar shop will match it.) If you can’t test the displays personally, make sure you buy from a vendor with a good return policy to avoid being stuck with a sluggish display.
For more information on buying displays, check our articles “How to Buy a Flat-Screen TV” and “How to Buy a Monitor.”