TFT

From QWiki

NOTE
Note in 2022: This article is outdated, as everyone uses "TFTs" (LCD screens) now, and they are fairly good understood.
This article is fed by Quakeworld.NU forum thread on TFT/LCD monitors. Please contribute

Introduction


This article pretends to be helpful when choosing a TFT monitor to buy and choosing the best settings for playing Quakeworld.
Although CRT Monitors are better for gaming, TFT/LCD monitors are on the rise. They're more technologically advanced than CRT ones but they're worse for gaming. Nevertheless, these are gaining popularity because they're better for everything else. Smaller, lighter, better to the eyes, great quality and good size makes LCD monitors the number 1 choice.


These days monitor brands have at least one 120hz tft monitor. These are *highly* recommended, in alternative to a big and heavy crt. Some models available today:

  • LG W2363D
  • BenQ xl2410t
  • Asus VG236HE
  • ViewSonic V3D245

If you own one 120hz tft monitor you can ignore the remaining information on this page, since these monitors usually deliver a very smooth experience out-of-the-box.



Overall Best Settings for QW


Shall I use my monitor's native resolution?
Depends on the size of your monitor and what graphic card you own.
Larger monitors have larger native resolutions, some of them unbearable for the mortal :) For example, wide 22' monitors have 1680*1050 pixels. That's fine in the OS, but for games is ZZZ. But if you can get high fps with your monitor's native resolution, then you can use it. If not, we would recommend using lower resolutions to reduce screen lag.

Note to rember, it is advised to use screen native resolution so that pixels are represented 1:1. Tham means, that you should not use buitlin screen rescale algorithms, cause they can introduce additional input lag (sometimes up to 3 frames).
Under Windows with Nvidia graphic cards you can tweak this settings in Nvidia Control Panel, you got few options in Display -> Adjust desktop size and position. There are two modes recommended:

  • Do not scale - which will result in black bars around the image. So if you got 1920x1200 and you run 640x480 then you will get vast amout of black borders. It will look bizarre. Example here.
  • Use Nvidia Scaling - which will use native screen resolution but nvidia drivers will scale image for you (algorithm delay unknown).


60hz or 75hz?
TFT monitors are currently limited to 75Hz. Thats 75 "screen updates" per second. See below for best settings for each monitor. Note that some screens accept diplay at 75Hz rate but in fact interpolate it back to 60Hz so you will get once per 15 frames dropped, wich may have nasty non-smooth side effects.

VGA or DVI?
There is a limitation of bandwidth using DVI especially with higher-res TFTs but this is affected by the monitor's capability of being single- or dual-linked and it really limits the possible fps. Huge monitors with huge resolutions are basically unable to have anything above 60Hz due to this DVI bandwidth limitation.
The difference between VGA and DVI input varies from monitor to monitor. Basically VGA input adds random noise (or snowing) to the picture, or moving "waves" in the worst case scenario, or reducing the sharpness of the image and/or accuracy of color prodution. Note that using DVI or VGA does NOT affect input lag or the screen processing time at all, so it's recommended that DVI is being always used.

Which monitor and which settings?


Viewsonic's vx922
res: 1280x1024
hz: 75
maxfps: 154 (308 was even smoother, but felt a bit "heavy", for lack of a better description
cl_nopred 0
cl_nolerp 0
pushlatency 0
Forced profile values from display control center:
8xFSAF (anisotropic filtering) - atm. you should avoid using gl_anisotropy in ezq 1.8, because it also affects your crosshair
2xFSAA (antialiasing)

Criticism


LCD dont refresh the entire screen, instead they 'morph' the image pixel by pixel. CRT refresh the entire screen, so you always get a brand new image, created in one go, rather than 1000s of pixels. The bluriness in LCD and CRT comes from how fast the images or pixels are refreshed. Most people can set their CRT to 60hz and see quite a blurry image. CRT uses an electron gun in a technique which basically 'morphs' all the pixels, 60 times a second (during 60hz operation, 120 times a second during 120hz, etc.) This means that LCD will actually be faster than CRT, if they update at the same hertz, because LCD selectively refreshes parts of the screen, while CRT mechanics force it to refresh the entire screen. (This is partly how lossless video compression streams achieve smaller file sizes, by excluding redundant data except for key-frames every couple of seconds.)

One legitimate criticizm of LCD is 'ghosting' which is the effect of the physical properties of low quality liquid crystal, which the visible phosphorus layer on CRT does not exhibit.

CRT and LCD can both have true blacks, and true colour, depending on the quality of the manufacturer. Most LCD have "grid resolution", although there are alternatives to CRT such as Plasmas, etc.

CRT are a lot heavier, and have a variety of health concerns, including headache/vision strain, and other important concerns.

LCD also have some important concerns to consider: http://en.wikipedia.org/wiki/LCD#Drawbacks

See also: Widescreen Guide

External Links


Quakeworld.NU forum thread
Response Time
Input Lag
CRT Monitors
LCD/TFT on Wikipedia
Widescreen Guide