Post your LCD's Input Lag

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korkow

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Sep 3, 2007
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I decided to test my now 4 year old LCD's input lag vs my old CRT monitor. If other people could post their Input Lag, it would be a great reference for extreme gamers looking for a minimal input lag. Anywas, here is my setup for testing:

Needed: a CRT monitor, a LCD monitor, a decent camrea, stopwatch program (http://www.xnotestopwatch.com/xnsw140.zip)

1) Setup both monitors near each other, both plugged into the same video card and set to "clone" mode (where both display the exact same thing)

2) Start the stopwatch program

3) Take a picture (in high shutter priority if possible) and subtract the time in milliseconds shown on the CRT from the LCD. That is your Input lag in ms.

My LCD, the Acer AL1715, has an astounding input lag of 2ms!
 
korkow said:
I decided to test my now 4 year old LCD's input lag vs my old CRT monitor. If other people could post their Input Lag, it would be a great reference for extreme gamers looking for a minimal input lag. Anywas, here is my setup for testing:

Needed: a CRT monitor, a LCD monitor, a decent camrea, stopwatch program (http://www.xnotestopwatch.com/xnsw140.zip)

1) Setup both monitors near each other, both plugged into the same video card and set to "clone" mode (where both display the exact same thing)

2) Start the stopwatch program

3) Take a picture (in high shutter priority if possible) and subtract the time in milliseconds shown on the CRT from the LCD. That is your Input lag in ms.

My LCD, the Acer AL1715, has an astounding input lag of 2ms!
Click to expand...

1) clone mode won't give you accurate results. The ports may not be synchronized.

A millisecond is 1/1000 of a second. The program you used only has a 1/100 of a second display.
 
Most LCDs update the screen every 16.6 milliseconds so that puts a damper on it too.
 
Nenu said:
Most LCDs update the screen every 16.6 milliseconds so that puts a damper on it too.
Click to expand...
LCD's are continually updating the screen, from top to bottom. When the refresh reaches the bottom of the screen, it instantly starts again from the top

In the program I used in this image, each bar is diplayed for 1 frame. You can see how both the monitor and the LCD render from top to bottom.
lag6.jpg
 
You need to use a splitter for acurate results. You also need to perform the test numerous times and average the results.
 
Yelnats said:
LCD's are continually updating the screen, from top to bottom. When the refresh reaches the bottom of the screen, it instantly starts again from the top

In the program I used in this image, each bar is diplayed for 1 frame. You can see how both the monitor and the LCD render from top to bottom.
lag6.jpg
Click to expand...

Aye, it takes 16.6ms to complete 1 cycle at 60Hz.
(1Hz refers to 1 complete cycle)
Setting most LCDs higher than 60Hz doesnt increase the update rate, that remains constant at 60Hz.
Instead they drop frames which can make motion look jerky.

I'll keep an open mind for now whether this will be a useful technique :)
 
Clone mode isnt accurate? hmm when I tested both of my CRT's (FW900 & G520P) they were displaying identical results with a timer running. (7800GTX 512mb) I figured since I was getting identical results with two CRTs then my LCD vs. CRT input lag results would be accurate.. my 20WMGX2 LCD was averaging 20-30ms behind my FW900 CRT.
 
An additional control testing two CRTs to calibrate for any input lag being caused by anything other than the panel itself would be wise as well. Thats why input lag numbers are so hard to come by, somewhat annoying to test.
 
mathesar said:
Clone mode isnt accurate? hmm when I tested both of my CRT's (FW900 & G520P) they were displaying identical results with a timer running. (7800GTX 512mb) I figured since I was getting identical results with two CRTs then my LCD vs. CRT input lag results would be accurate.. my 20WMGX2 LCD was averaging 20-30ms behind my FW900 CRT.
Click to expand...

In some cases with some cards it is not %100 synced up. Repeating the test after switching what monitor, is on what connector, and what monitor Windows considers the primary should solve this concern, providing the results average the same. Also lcd lag is not a static value. Some situations, what is being displayed, and the lcd's settings can alter the lag.

The only lcds I have left are 2405 and a BenQ fp93gx 19" tn. I did test the BenQ last year against a 21" Sony flat Trinitron. I don't remember the exact numbers now but I think it was in the 30 to 50ms range depending on the situation. Not that I care about that lcd anyway, the pq is so bad on it I thought it was defective when I first plugged it in. It collects dust as an emergency spare. I only use the 2405 for web surfing, so I don't really care about it's lag numbers either I suppose.
 
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