High-definition TVs display fantastic images that make movies and TV shows come alive like never before. But playing video games on an HDTV can be rather tricky, especially if they require precise timing, like Rock Band or the latest version of Tiger Woods PGA TOUR®­. I'm talking about "gaming lag" — a very small but noticeable delay in the amount time it takes an HDTV to display images from a video game console. And a delay in how long it takes for your actions on the controller to register on the TV screen.

So what is it?
Every HDTV has a fixed, or "native," resolution, such as 1080p or 720p. An HDTV must convert any incoming signal, no matter what the source, to its native resolution. Unfortunately for us gamers, this conversion takes time; time that can mean a delay of up to a few frames of video or more. So with many HDTVs, where you see that colored note on Rock Band isn't where it "really" is; it's actually off by a few frames due to the amount of time it takes for the TV to convert the signal to its native resolution.

As you might guess, lag time will be the longest when the resolution of your console doesn't match the resolution of your HDTV. Playing a standard-definition console like the Wii™ or PS2 on a 1080p TV will result in the greatest lag, while a high-def console like the Xbox 360™ or PS3 running on this same TV may not lag at all.

Gaming lag also stems from the fact that most HDTVs are designed to display eye-catching images with extraordinary detail, depth, and color accuracy. Many of them include extra video processing to achieve this goal. However, these TVs are built for beauty, and not speed. This extra video processing also takes time, which can make the lag even worse.

Gaming lag — first hand
Since getting an HDTV a few months ago, I've had some first-hand experience with gaming lag. I noticed it the first time I fired up Guitar Hero™ II (PS2 version) on my new HDTV. I had heard about gaming lag before, but never had the chance to experience it personally. I missed notes left and right, including ones that I knew I hit. Guitar Hero II includes a utility that calculates your HDTV's lag, so I ran it to see what it would tell me. Sure enough, it said I had a lag of approximately 100ms. That may not sound like much, but that's 1/10 of a second — a big deal when you're playing a game that requires precise timing.

Now, I don't mean to alarm any gamers who are shopping for an HDTV. Lag may be an issue for games that require precise timing like music and sports games, but not for other types of games like turn-based strategy ones. While I enjoy the occasional round of Guitar Hero, my main gaming passion is Japanese RPGs, particularly the old-school turn-based kind. Lag was the furthest thing from my mind during my recent playthrough of Persona 3 FES.

Game Mode
Thankfully, many HDTV manufacturers, such as Sony, Samsung, and Toshiba (their 52" REGZA® LCD HDTV's pictured above), include a "Game Mode" to eliminate or minimize gaming lag. Game Mode speeds up image processing time, and often turns off any extra video processing designed to make movies and TV shows look their best. My TV has such a mode, and it lowered the amount of lag in Guitar Hero II from 100ms to 24ms. That's a definite improvement, and I'm now playing like I was on my old, lag-free CRT set.

Theoretically, game mode may lead to a small drop in image quality, but I sure haven't noticed it. So if you're looking for an HDTV and you plan on rocking out with Rock Band or challenging Tiger Woods to 18 holes at Sawgrass, make sure you pick out a set with a Game Mode.