HDTV gaming lag - IGN Article explains in simple terms

03:08 AM

I am posting this in H3G at the request of Cursed Lemon.

IGN Entertainment

HDTV-Gaming-Lag: An Epidemic Exposed

Some HDTVs can make videogames unplayable. We explain the phenomena, the causes, and the solutions.

by Gerry Block

June 12, 2006 - Over the course of the months that our HDTV Q&A series has been running we've been deluged with comments regarding HDTV-gaming-lag. From questions as to which models are most susceptible to sad stories of new purchases leading to great disappointment, we know it's a serious issue for gamers planning to make the jump to HDTV, or those who got stuck with an HDTV that is making games unplayable. In this feature we aim to identify and explain what HDTV-gaming-lag is, what causes it, and various ways to overcome the problem.

The Problem

If you're new to the issue, we should start by explaining what HDTV-gaming-lag is all about. Not all HDTVs suffer from a noticeable amount of lag, and not all for the same reasons, which makes the whole issue a little difficult to nail down. However, the simplest explanation of the phenomena would be that some HDTVs generate lag (sometimes as much as half-a-second) while processing incoming signals and getting the image on the screen. The effect isn't terribly noticeable in most applications, however, videogamers quickly realize that there is a problem when they execute commands and only get an on-screen reaction noticeably later. Lag of a half-second, or even much less, can make music, rhythm, sports, fighting, FPS, or just about any other genre of game essentially unplayable, and is thus a serious problem.

Why does the lag occur? There are two related answers to this question. The first is the issue of native resolutions. Every TV, be it High-Def or Standard-Def, has a native resolution--a fixed display quality. Old-school CRTs are 480i, while more modern EDTVs and HDTVs run the gamut from 480p to variations of 720p (1024x768 [lower res than true 720p], 1280x720 [real 720p], and 1366x768) to 1080i and 1080p (1920x1080), as well as some odd resolutions in between.

Just as every TV has a native resolution, just about every source has a particular resolution as well. Every console that came before the PS2 produced a 480i signal. The PS2 was primarily a 480i system with a few 480p games, while the GameCube and Xbox were both primarily 480p, with a few 480i games and, in the case of the Xbox, a couple of 720p games. The Xbox 360 is able to output 480p, 720p, and 1080i, though the majority of the games are designed with 720p in mind. The Nintendo Wii will be a constant 480p. The first generation of HD-DVD players output 1080i as their native resolution, while the first generation of Blu-ray players will output native 1080p.

Here's the meat of the native resolution issue: While just about any HDTV can accept any other signal, like a 1366x768 native resolution HD-LCD accepting a 1080i signal from an HD-DVD player, the incoming signal must be scaled to match the native resolution of the TV, in this case down from 1920x1080 to 1366x768. This sort of processing takes real work to accomplish, which is handled by the internal scaling circuitry of the HDTV. The heaviest load usually occurs when an HDTV must up-scale a 480i signal to native resolution, which requires both enlarging the image and converting the signal from interlaced (the 'i' in 480i) to progressive-scan (the 'p' in 480p, 720p etc.).

Some HDTVs handle this task better than others; however, almost all models will develop at least a little lag in the time it takes them to up-scale an old-school 480i signal. This becomes a problem for retro-gaming fans who aim to play their 16-bit consoles on their expensive new HDTVs. Some HDTVs even produce a game-killing degree of lag when working with 480p or any signal that does not exactly match the native resolution of the TV itself.

The second cause for HDTV-gaming-lag is some HDTVs' image-enhancement processing, a related issue of image-scaling. Most common in older HDTVs that aimed to make DVDs and other Standard-Definition content look good compared to competing models, internal image enhancement spends time refining incoming signals before putting them on-screen. Samsung's DNIe technology is a well known variant of this technology. While image-enhancement can certainly help make HDTVs look better, most manufactures did not worry about introducing a degree of lag as a result, as the only application on their minds was DVD and TV signals, cases in which a half-second delay would hardly matter. For gamers, however, heavy image-enhancement can seriously add to the time it takes for commands executed in-game to make their way onto the screen.

As we mentioned earlier, some HDTVs are better at scaling and generating lag-free videogaming than others. While there can't be any hard and fast rules, HD-CRTs are generally credited with producing the least amount of lag, while DLP-based HDTVs (Samsungs in particular thanks to DNIe image enhancement) are often considered the worst. Of course, we've read a number of reports of laggy LCDs and plasma displays as well, which means that no HDTV technology is truly safe.

The Solutions
The best solution to HDTV-gaming-lag is to avoid it all together. If at all possible, if you're in the market for a new HDTV, go to a retail store with your game consoles in hand and ask to plug them to the models you're considering purchasing. Bring the consoles that are important to you, and keep in mind that you'll want to check performance with 480i signals (retrogaming), 480p (Wii, PS2), and 720p / 1080i (Xbox 360). Bring games that require accurate timing that you are familiar with, as you may discover a .2 second delay that isn't visually visible but can still ruin your 30 hit combo in Marvel vs. Capcom 2. The salespeople should be accommodating, though it's likely you'll find yourself having to explain the lag issue if they aren't serious gamers.

If you've already got your hands on an HDTV that is producing gaming lag, all is not lost. The first step is to consider potential work-arounds that don't require new hardware. A key first step is attempting to match the incoming signal to the HDTV's native resolution. For example, if you have a 1280x720 native resolution LCD, make sure you set your Xbox 360 to 720p output. If you have a 1080i native-res HD-CRT, set your 360 to 1080i output.

Some HDTVs on the market today have special 'Game Modes' that disable image-enhancement modes to product less lag. Paging through your manual or a good Google search is your best bet for discovering if your HDTV has an option of this sort.

http://gear.ign.com/articles/712/712352p1.html

So there is a list out there that says which tv's are best for little or no lag? Or do you have to test them all out??

Quote:

Originally Posted by RVideo

The Solutions
A key first step is attempting to match the incoming signal to the HDTV's native resolution. For example, if you have a 1280x720 native resolution LCD, make sure you set your Xbox 360 to 720p output. If you have a 1080i native-res HD-CRT, set your 360 to 1080i output.

I just helped a friend with this the other day. I had experienced the same problem with my dads TV as well, but I found out how to fix it a long time ago. Nonetheless nice post.