Originally posted by: nytmarezz
xtknight,
Thank you very much for taking the time to answer my questions but I have just a few more if you don't mind.
____.1a
Like I mentioned my usage patterns are mostly gaming so when I hear you mention input lag and I see horrifying comparisons on youtube between a CRT and an LCD that gets me very concerned. The video I am talking about (which I can't link to at the moment since I am at work) shows a Dell 2407FPW and some CRT. While the response time on the 2407FPW seems fully capable of displaying the high FPS its obviously lagging behind the CRT enough that you can actually see it when the player makes fast moves. A quick search for "lcd input lag" would probably find the video in question very quickly.
Sorry, but these "experimentations" are largely non-scientific and people make sweeping conclusions based off of them. The main thing people miss is that humans learn to adapt to such things as input lag. If anyone compares it to network lag (bidirectional), they do not know what they are talking about. Lag on network makes play difficult mainly because of misprediction by the game engine, causing misplaced shots. That is not anything like a slight lag on the output device.
I believe that there will be very little disadvantage, even in fast-paced games, when using most LCDs. In more extreme cases, like using a 50 ms input lag Dell 2407, there may be some very minor consequences. Anyway I think it is rather ridiculous to obsess over that stuff unless you game a competitive league like CAL, or perhaps if you're on online ladders. There are many people who just game casually and for those, those LCDs without a doubt are fine. Those complaining of obnoxious input lag have simply not allowed themselves to adapt to it. Switching from a 0 ms lag CRT to a 50 ms lag Dell 2407WFP may not be the easiest transition. After all, even switching to a more conventional LCD like a 19" (assuming it has RTC) will involve around 16 ms of input lag already. Even that takes time to adapt to.
Based on your reply regarding the input lag and response time between a 22" [vs] 24" TN panels would it be thus safe to presume it comes out to something like this: The higher the resolution and/or the bigger the moniter = higher input lag? Likewise do all the other panel types (PVA/MVA) have higher input lag than TNs?
That's pretty much true. It does seem that most PVAs and IPSs have a higher input lag than TNs, but that's probably because they use RTC a lot more as it is pretty much essential on PVA/IPS panels.
____.1b
If yes to the above question, how big of a difference are we talking about between sizes/resolutions/panel-types?
We don't know for sure. As far as I know, input lag is due to the overdrive buffer, which shouldn't get bigger due to resolution. It just so happens that the biggest LCDs with high resolutions use PVA and IPS panels the most, and those use overdrive the most. Some may use even more aggressive overdrive (3 or 4 frames stored = 32ms). As to why we're hitting 50 ms of input lag, I simply don't know. There is no concrete info.
____.2a
Ok regarding the 100Hz LCDs again. I'll just explain how I understand the whole refresh [vs] response situation and you can just tell me if I'm right, somewhere in the middle or just flat wrong.
Current LCDs usually run at a 60Hz refresh rate at their native resolution. That means they cannot display more than 60 images per second regardless of how many your your video card is sending or how low their response time is. At the maximum that would translate to a response time of 16ms (1000ms/60Hz = ~16ms).
You are comparing the time at which it takes the whole screen to update compared to how long it takes a single cell to update. The comparison is invalid because no cell on the LCD transitions at exactly the same speed as another. And, for example, it can take twice as long to transition from red to gray as it does to get from red to blue.
So technically, until the refresh rate is increased, response times faster than 16ms are useless since they cannot be fully utilized. However since (as far as I know?) very few LCDs are capable of a 16ms response time (from full black to full white) the issue is moot for now. In that sense refresh rate "doesn't matter" on LCDs since the response time isn't low enough YET to actually make a difference.
Response time on LCDs is a very confusing thing (I don't even really understand all the mechanics). When you put overdrive in the picture it is even more complicated. Making a transition from a pure red to a pure blue is usually very fast, as is any transition from one fully bright color to another. That's because (in the case of red->blue) overdrive can send a strong impulse to turn off the red subpixel and turn on the blue one without worrying that much about going over, since we are requesting the brightest color anyway. Even natively, I believe TFT screens are faster at going from one extreme to another, versus going from one gray to another gray because the precision at which they must twist isn't as crucial when you just want to get from extreme A(0) to extreme B(255). The notion that gray-to-gray is an inaccurate measurement and is always faster than black-to-white is just plain false because it is based off a false assumption.
Many LCDs are capable of reaching under 7 ms for any possible transition (although they due suffer some RTC error, which technically should increase the response time). Black to white response time is probably around 2 ms on the fastest LCDs now. In fact, one direction (black->white or white->black) is faster than CRTs in some cases. Move a white cursor on a black screen on a CRT and a TN LCD, even without overdrive (e.g. Samsung SyncMaster 710T). You will notice that the CRT has more ghosting (due to its phosphors). It's intermediate transitions where the most problems occur.
Let's take a look at the fastest TN in the world, the BenQ FP93GX:
http://www.xbitlabs.com/articl...isplay/19inch-4_9.html
( Close competitor with the LG L1970HR (which I should relist now that availability of the BenQ is limited) ):
http://www.xbitlabs.com/articl...splay/19inch-5_16.html
Both are very fast, but it looks like the L1970HR is able to reach under 6 ms for all the transitions. Worst RTC error is 43.7%. So you can add that to 6 ms (6ms + (.437)*6ms) = 8.622 ms full transition time, worst case. (And then there's the input lag which wasn't measured, but can't be much worse than most 19" TNs.) Input lag of the LG L1960TQ (different one) is {0, 7.6, 25} (min, avg, max).[1]
[1]
http://www.lesnumeriques.com/d...&mo2=112&p2=1134&ph=12
____.2b
If my understanding in the above is correct: are higher refresh rate LCDs, capable of truly showing higher FPS not through some "cheat" or other technology, in our near future?
I still don't quite understand how a couple LCDs are capable of showing a higher refresh rate. Many have said that they skip every fifth or sixth frame to convert it to 60 Hz, but if so it's doing a pretty good job. I have used 75 Hz on the ViewSonic VP930b next to me, for years, and I've enjoyed the perceptually smoother motion. This seems to be a feature no manufacturer really cares about much. It's just something that is slapped on as a feature to the DSP if they feel like it. Some just get lazy and limit every res to 60 Hz. I've heard absolutely nothing about the future in this regard.
____.3
I looked at the CMO panels mentioned by you earlier in this thread and the M240J2-L01 sounds interesting. It has a low response time and since its not using RTC that should help reduce input lag (right?). I'm assuming its going to be 1920x1200. If it's already gone into mass production, how soon do you think we will start seeing this on the market?
Yes, it should reduce the input lag. I'm also interested to see how the Samsung 245B[W], a 24" and I
believe RTC-less TN, performs. I have no idea when CMO's 24" TNs will be on the market, or even if they will. That was some confidential info I just happened to stumble across (google M240J2-L01).
I'm betting we will see a lot more LCDs based on the Samsung 24" TN panel very soon.