Hi all,
Last year, I posted a review / comparison of two 24" LCD screens, the Samsung 243T and the Dell 2405fpw. One of the my main conclusions was that the 2405fpw has indeed much improved color and better pixel response time (and hence less motion blur / ghosting), but that it apparently suffers from a signal delay compared to the 243T. You can read it here:
Dell 2405fpw VS. Samsung 243T - Dell has Lag!!
This time, I compared my 2405fpw against a Sony Multiscan E210 Trinitron 17" CRT, taking a photo (1/60sec) that shows both screens at the same instant. The screens are cloned displays on my Radeon X800, showing a timer (A.F.8 Digital Clock, downloaded from http://www.fauland.com/af8.htm). Of the three digits that you see, the first is seconds, and the last digit gives 1/100 seconds:
Specifications: 2405fpw as primary display using DVI, E210 as cloned secondary display using VGA, 1280x768 pixels, 60Hz refresh rate.
As you can see, the 2405fpw trails behind the CRT by up to 40ms. In most other photographs, the difference was 30ms, but due to the timer resolution and screen refresh rate the exact time delay cannot be defined more precisely.
Unfortunately, I don't have the 243T anymore to perform this experiment, but my guess would be that the 243T is probably 15-20ms slower than a CRT.
Again, this shows that while a CRT works in "real time", LCDs can (and do) have signal latency issues, because they do some fancy digital signal processing. The situation is similar in nature to the fact that analog music amplifiers work in real time, whereas dolby digital receivers can have a small - but occasionally annoying - delay due to the digital signal processing of the audio data.
I would encourage others to test their LCDs in a similar way against a CRT and post figures. Furthermore, I would suggest we ask that LCD manufacturers specify the signal latency of their LCD's electronics, and not just the pixel speed once the signal actually arrives at the pixel.
For online gaming especially, this sucks. You'll have a competitive disadvantage that is at least equivalent to having 40ms added to your ping, or worse. I'm not entirely sure yet if 40ms extra ping on a CRT are exactly the same as playing on the 2405fpw, or if there are other effects to consider, like the fact that not even local events are displayed in real-time on your screen.
I play UT2k4 on occasion, and for fun I tried playing it on that tiny 17" CRT. My eyes started to hurt, but my performance and target accuracy seemed better indeed.
Comments welcome.
Last year, I posted a review / comparison of two 24" LCD screens, the Samsung 243T and the Dell 2405fpw. One of the my main conclusions was that the 2405fpw has indeed much improved color and better pixel response time (and hence less motion blur / ghosting), but that it apparently suffers from a signal delay compared to the 243T. You can read it here:
Dell 2405fpw VS. Samsung 243T - Dell has Lag!!
This time, I compared my 2405fpw against a Sony Multiscan E210 Trinitron 17" CRT, taking a photo (1/60sec) that shows both screens at the same instant. The screens are cloned displays on my Radeon X800, showing a timer (A.F.8 Digital Clock, downloaded from http://www.fauland.com/af8.htm). Of the three digits that you see, the first is seconds, and the last digit gives 1/100 seconds:
Specifications: 2405fpw as primary display using DVI, E210 as cloned secondary display using VGA, 1280x768 pixels, 60Hz refresh rate.
As you can see, the 2405fpw trails behind the CRT by up to 40ms. In most other photographs, the difference was 30ms, but due to the timer resolution and screen refresh rate the exact time delay cannot be defined more precisely.
Unfortunately, I don't have the 243T anymore to perform this experiment, but my guess would be that the 243T is probably 15-20ms slower than a CRT.
Again, this shows that while a CRT works in "real time", LCDs can (and do) have signal latency issues, because they do some fancy digital signal processing. The situation is similar in nature to the fact that analog music amplifiers work in real time, whereas dolby digital receivers can have a small - but occasionally annoying - delay due to the digital signal processing of the audio data.
I would encourage others to test their LCDs in a similar way against a CRT and post figures. Furthermore, I would suggest we ask that LCD manufacturers specify the signal latency of their LCD's electronics, and not just the pixel speed once the signal actually arrives at the pixel.
For online gaming especially, this sucks. You'll have a competitive disadvantage that is at least equivalent to having 40ms added to your ping, or worse. I'm not entirely sure yet if 40ms extra ping on a CRT are exactly the same as playing on the 2405fpw, or if there are other effects to consider, like the fact that not even local events are displayed in real-time on your screen.
I play UT2k4 on occasion, and for fun I tried playing it on that tiny 17" CRT. My eyes started to hurt, but my performance and target accuracy seemed better indeed.
Comments welcome.