once again -> is there a decent 24" lcd out there? (2405fpw no need to apply)

[velis]

Input lag is actually the time DSP takes to process one frame and applies it to the actual pixels on the monitor. That means you get the image you requested (gfx card sent) with some delay of up to say 100ms, typically <50ms.

But that's it!!!!!! No other gameplay issues, no network lag, no nothing! It's entirely monitor based issue. The monitor will still receive your next frame to be displayed in the next cycle and your CPU + GPU will still process their next frame. All you "will notice" is that the actual image on the display lags the sound output by some <50ms. And don't tell me you're capable of noticing that?!?

I guess there should be some difference in implementation for various monitors. 60Hz = ~17ms which means a monitor with 40ms input lag should have at least 3 full screen buffers to not skip any frames. If it has only one, well then your actual refresh in this case would be 20Hz since the monitor would have to ignore the following two frames when preparing the one in it's buffer. Somehow I don't believe that's the case in any monitor since even 2560 * 1600 requires only about 12MB of RAM. What's a 32MB chip cost nowadays? I don't know how the panels are actually implemented. It could be that one chip drives the whole thing, but i believe it is far more likely that the panel itself contains transistors that handle individual pixel logic and DSP only feeds those transistors. The implementation of such triple buffering is in such case even easier since you only have to have a few SRAMs or tiny capacitors there to buffer it for you.

 

[darXoul]

Originally posted by: Madellga
Human reflex lag is higher than 50ms. I doubt also than you call tell a lag of 30-50 without measuring hardware.

This is, simply put, not true. It's one of the "human eye cannot see more frames per second than 30" opinions. 50 ms of lag is not only noticeable, it's a horrible handicap for competitive gaming. 30-50 ms lag won't matter much in slow-paced, single player gaming. For let's say, a Q3 CPMA 1v1 game, it will be awful. The difference between e.g. 50 ping and effective 100 ping (network delay + input lag) is day and night.

All people talking big about theory, DSP, fps and not being able to notice input delay have obviously the reflexes of a chess player (no offence, chess players) and have never really tried any competitive FPS gaming.

If I press my mouse button to fire a railgun shot and the monitor reacts after 65 ms like the Samsung 244t seems to react in some situations, not even mentioning the regular network lag, the LCD isn't worth a penny in my eyes. Other users with other needs may be satisfied or even delighted. I would be just disappointed and sell/return the display in a heartbeat.

 

[velis]

You are, of course, right, DarXoul. If monitor lag represents 10% of average human response time then it's more likely that your opponent will already have fired at you before you fire at him. 10% is, after all, quite a lot. However, the OP specifically said that he doesn't game, let alone play "fast paced competitive" games. I say he's not going to notice even a 100ms lag watching movies. It does make some difference in scenario that you mention, but nowhere else. You can make up for those 40ms by getting yourself a nice good night sleep instead of playing 24/7. That's what you seem to do since you require such lightning fast reflexes. Somebody trying to explain how stuff works doesn't necessarily have reflexes of a chess player, as you put it. They are explaining, not playing!
That said, I'm dumping my CRT for a good 24" LCD in the next few months since I only play single-player games on my comp. My reflexes actually do suck, but not because of my monitor. I don't need them for programming

 

[xtknight]

---never mind, it's just going to start more flame wars anyway.

 

[CP5670]

A 50ms delay in everything would drive me nuts just moving the mouse in Windows. I find even the 16ms response time on my laptop LCD to be a little annoying in this respect, although this display may have its own input lag issue. Does it also happen on smaller LCDs or on an analog VGA connection?

 

[davet11]

Originally posted by: CP5670
A 50ms delay in everything would drive me nuts just moving the mouse in Windows. I find even the 16ms response time on my laptop LCD to be a little annoying in this respect, although this display may have its own input lag issue. Does it also happen on smaller LCDs or on an analog VGA connection?

Thank you. I'm fairly certain that although I don't do any competitive gaming, the general feeling of "sluggishness" would annoy me, even if it is just a little bit. Especially doing cad/3d stuff, I seriously think it would get on my nerves.

 

[xtknight]

The Dell 2405FPW and Samsung 244t have gotten reports of input lag, so I think you'll be safest with the Philips. We haven't heard hardly anything about the Philips so you're taking a chance there. It's a different type of panel from the Dell and Samsung from a different manufacturer so maybe it won't have the problem. The Dell 2405FPW and Samsung 244t both use the same Samsung S-PVA panel, and the Philips 23" widescreen uses an LG Philips LCD S-IPS panel.

 

[Markbnj]

And there are dozens of complaints of it happening with both the Samsung 244t and the Dell 2405fpw. But then there are plenty of people who say there's no problem at all.

That's often a hint that the problem is subjective.

We're using basically the same DSPs that we were to do 1280x1024 to do 1920x1200. And they just can't keep up. So when you move your mouse, in your computer, it happens instantly, but there's a delay inside your monitor in displaying your cursor move.

If that's true, then it is the whole frame that is being delayed, not just the mouse cursor, since the monitor doesn't know that the little blob of white pixels is a mouse cursor. I'll have to do some more research into this, but I remain skeptical, and don't experience any such issues myself.

That means you get the image you requested (gfx card sent) with some delay of up to say 100ms, typically <50ms.

100ms? You're saying that a panel that refreshes at 60hz takes up to 100ms to process a frame through?

Edit:

I spent an hour or so trying to find some hard data on this issue, and 97% of what is out there is speculation and very subjective. The rest consists of attempts to demonstrate lag between a CRT and an LCD using various approaches at software and hardware timing.

Some, if not all, of these timing approaches have potential flaws, in that they don't isolate the various stages in the frame rendering pipeline. However, given some of the academic work that has been done it seems safe to say that LCD panels lag as much as one frame behind a CRT displaying the same image. One frame is in the neighborhood of 16-17ms. That does not seem surprising to me, given the inherent differences. As to whether it is significant, consider that there is between a 5-16ms delay between drawing the top of the screen and the bottom of the screen on a CRT. I don't recall people complaining about aiming difficulty in FPS games when aiming low.

There is also a very real issue when a panel is forced to upscale an image to its native res. There has been a lot of discussion on this topic surrounding HDTVs and consoles that drive 480i displays. Would be interesting to see someone do some tests with the 360 on 1080p.

From my reading, the net/net here is that LCDs are slower than CRTs. I think we already knew that. Those who are happy with LCDs have elected to live with the tradeoff, and after all even 40 fps is more than acceptable for full motion video.

I saw nothing that convinces me there is a significant difference between brands of LCD panels, other than that accounted for by the different response times.

 

[darXoul]

Originally posted by: velis
However, the OP specifically said that he doesn't game, let alone play "fast paced competitive" games. I say he's not going to notice even a 100ms lag watching movies. It does make some difference in scenario that you mention, but nowhere else.

I'm not sure this is true. 100 ms lag would be annoying even in regular desktop work and SP gaming. For movies, I couldn't care less, of course. I wasn't referring to the OP's needs, rather participating in a general discussion.

Originally posted by: velis
You can make up for those 40ms by getting yourself a nice good night sleep instead of playing 24/7. That's what you seem to do since you require such lightning fast reflexes.

You couldn't be more wrong. If you picture me as a 14-year old e-sport freak, as you seem to, it's about time to verify this perception. I'm twice as old and barely a hardcore gamer now. You know, if you work every day from 9 to 5-8, you hardly have any time for games. In other words, your shot was quite a bad miss Maybe your aim was lag-impaired

Originally posted by: velis
Somebody trying to explain how stuff works doesn't necessarily have reflexes of a chess player, as you put it. They are explaining, not playing!

See my comments above. My point is very simple: if someone who plays fast games ever asks me here whether I recommend a monitor like 2405fpw or 244t for gaming, I'd say "beware, it may kill your gaming with input lag". YMMV.

Originally posted by: velis
My reflexes actually do suck, but not because of my monitor. I don't need them for programming

Mine do not - actually they were a prerequisite to be a good junior table tennis player I don't need them for my banking work, but when I play Q3 CPMA (which I still love and try to play for fun at least once per week), I don't want my monitor to bother me with 100, 50 or even 20 ms of additional lag.

 

[FalllenAngell]

Love my 2405FPW as well, works great for gaming, with the exception of UT2004 online. For some reason it plays differently online that it does single player, which is not the case with my CRTs.

 

[MercenaryForHire]

Here's how you determine if your monitor has input lag or not.

1) Load up Q3A/UT2004/other FPS game.
2) Launch a single player game vs one weak bot, and crank the speakers.
3) Whip out the railgun/sniper rifle/instant-hit, very noisy weapon.
4) Zero in on the poor CPU's head and click your mouse. ( If you're some sort of heathen who doesn't use LMB for weapon fire, do your voodoo dance with chicken blood and black candles, or whatever. )

Since your body and mind know when you're going to pull the trigger, human response time will be negligible as it's a predictive activity and not a reactive.

If the gunshot is heard before the head goes pop, your display is lagging.
If they're heard at the same time, it is not.

- M4H

 

[velis]

I have this crazy idea about testing this input lag. Tell me if I'm wrong somewhere:
We're getting a Samsung 244T at work this week. I find this really convenient since this is exactly the monitor I'm aiming for for my home .
I will have Sony G420 (CRT), Samsung 213T, Samsung214T and Samsung244T at my disposal. We also have a relatively high quality IP camera (JVC - 30FPS) here.
Suppose I set all the monitors to 60Hz refresh and write a small program that does the following:
1. Change screen pattern
2. Start counter
3. Grab image from camera
3.1. Store timer
4. Compare image with previous one
5. If images differ > 10% then monitor has shown the new image
6. Otherwise goto step 3
7. Save stored timer to a table
8. goto step 1 for a 1000 times
9. Average (arithmetic) the timers in the little table
Display the average number

I can repeat this on all 4 monitors and then report the averages to you guys. This way we could easily determine what response each of these monitors has.
The camera would of course have to be set to minimum picture quality (resolution) so that grabbing would be as fast as possible.

Would this method be acceptable by everyone?
I need suggestions for the patterns (They must have high contrast among themselves since I don't exactly excel in image delta algorithms).
If anybody can point me to a good (and fast) delta algorithm, I'd appreciate it as well. Otherwise I'll just cmp hues in 8x8 blocks

 

[davet11]

Originally posted by: velis
I have this crazy idea about testing this input lag. Tell me if I'm wrong somewhere:
We're getting a Samsung 244T at work this week. I find this really convenient since this is exactly the monitor I'm aiming for for my home .
I will have Sony G420 (CRT), Samsung 213T, Samsung214T and Samsung244T at my disposal. We also have a relatively high quality IP camera (JVC - 30FPS) here.
Suppose I set all the monitors to 60Hz refresh and write a small program that does the following:
1. Change screen pattern
2. Start counter
3. Grab image from camera
3.1. Store timer
4. Compare image with previous one
5. If images differ > 10% then monitor has shown the new image
6. Otherwise goto step 3
7. Save stored timer to a table
8. goto step 1 for a 1000 times
9. Average (arithmetic) the timers in the little table
Display the average number

I can repeat this on all 4 monitors and then report the averages to you guys. This way we could easily determine what response each of these monitors has.
The camera would of course have to be set to minimum picture quality (resolution) so that grabbing would be as fast as possible.

Would this method be acceptable by everyone?
I need suggestions for the patterns (They must have high contrast among themselves since I don't exactly excel in image delta algorithms).
If anybody can point me to a good (and fast) delta algorithm, I'd appreciate it as well. Otherwise I'll just cmp hues in 8x8 blocks

Definitely a solid idea, although I don't think you need to make it as complicated. If you look on the hardforums, they have tested in a variety of ways such as running a clock that has milliseconds on both screens at the same time, then seeing if there is a difference. Or stretching a window across both screens, moving it up and down, and recording it in video, then slowing it down to see the difference.

Your test would be killer though, since it would finally give an idea of a "few" monitors, rather than just 1 or 2, great idea, just don't want you to have to go through too much trouble.

 

[Madellga]

Originally posted by: darXoul

Originally posted by: Madellga
Human reflex lag is higher than 50ms. I doubt also than you call tell a lag of 30-50 without measuring hardware.

This is, simply put, not true. It's one of the "human eye cannot see more frames per second than 30" opinions. 50 ms of lag is not only noticeable, it's a horrible handicap for competitive gaming. 30-50 ms lag won't matter much in slow-paced, single player gaming. For let's say, a Q3 CPMA 1v1 game, it will be awful. The difference between e.g. 50 ping and effective 100 ping (network delay + input lag) is day and night.

All people talking big about theory, DSP, fps and not being able to notice input delay have obviously the reflexes of a chess player (no offence, chess players) and have never really tried any competitive FPS gaming.

If I press my mouse button to fire a railgun shot and the monitor reacts after 65 ms like the Samsung 244t seems to react in some situations, not even mentioning the regular network lag, the LCD isn't worth a penny in my eyes. Other users with other needs may be satisfied or even delighted. I would be just disappointed and sell/return the display in a heartbeat.

What a salad!! You're mixing all lags together and they mean different things for gaming. Network lag is accumulative, meaning you add your lag to the players on the server. That makes gameplay difficult. And we are talking here 150ms to 300ms, which anyone normal call tell.

This ditto monitor lag people talk about cannot be "perceived" by us. I'm not talking about fast or slow LCD panels.

The only person who can work in 50ms timeframe is The Flash

 

[Geomagick]

I have found that the single biggest cause of lag in my system is the user and not the kit. I see this hasn't been mentioned but is it possible to turn off some of the more advanced DSP functions within the monitor if it really is that important.

 

[yacoub]

Originally posted by: Nebor
I can explain input lag to all of you non-believers.

Now, believe it or not, magic doesn't just make your video card's output appear on the LCD screen. Oh no, the monitor has a processor of it's own, called a DSP, or digital signal processor.

Now as we've gotten these larger and larger panels with nice fast response times, and increased resolutions, DSP technology hasn't exactly kept up. We're using basically the same DSPs that we were to do 1280x1024 to do 1920x1200. And they just can't keep up. So when you move your mouse, in your computer, it happens instantly, but there's a delay inside your monitor in displaying your cursor move. This presents a rather serious problem in video games.

And there are dozens of complaints of it happening with both the Samsung 244t and the Dell 2405fpw. But then there are plenty of people who say there's no problem at all.

"Input lag" is system dependent. That is why not everyone experiences it. Not everyone is getting it. It depends on many factors, including the performance of one's GPU, the games played, and the user's input devices. Wireless mice seem to add lag, weak GPUs add lag, and graphically-intensive games (as in, not WoW) at full 19x12 res, exhibit the most obvious lag.

This is why I can go into CompUSA and experience NASTY input lag on the system they have running a 1920x1200 23" Widescreen monitor with a wireless mouse, X700 GPU, and just on the Windows desktop, yet my old roommate's 2405FPW on a 7800GT system running WoW full res exhibits pretty much no input lag.

 

[velis]

Well, i checked out the HardForums and some of the relevant threads there. After reading through all of that I have some interesting obsevations (at least I think they are interesting )
1) All the testing methods used there never accounted for LCD latency which is real and manufacturer stated albeit always stated lower than it really is
2) I have not for one test seen the tester tell us what refresh was used for CRTs. (200Hz vs 100Hz means 5ms, 100Hz vs 60Hz means 7ms)
3) Nobody connected the LCDs through analog even though that would introduce additional conversion delay. But this is actually the only possible way that the gfx card would treat the monitors the same.

For example, there was a tester comparing 2 cloned displays with clock showing on the screen (milliseconds). The LCD in question was 2005FPW. He has shown that the LCD lags behind the CRT about 25 - 45ms.

20ms is the displays latency as measured by Toms Hardware in their 16:9 display article. So we're down to 5 - 25 ms which is probably the real input lag. This lag is quite possible since the LCD works with digital signal even if you use 15 pin analog connector (it will just get converted twice then ). Note that the methodology used and the simple major differences in time among various screen refresh rates simply make the max lag timing invalid. The actual times should be reduced from the start since 60Hz refresh rate of the LCDs makes any one picture appear in 17ms, even if windows has refresh rate set to 100Hz. So we're down to 0 - 18ms for Dell display, 18 - 38ms for Samsung. This is for this review only. One should note that the difference for the two CRTs should go from 0 - 17ms as well if they were handled differently as in 15pin vs DVI.
I won't even go into other tests shown there since they all show about the same.
I will state some other things though:
1) There were quite a few posts of ppl performing the same tests and coming up with at most 10ms difference. Edit: I'm beginning to think the actual gfx card used contributes significantly to this lag.
2) There were ppl reporting that they were able to "fix" the issue with drivers' DVI settings
3) The resolution of these displays is much higher than what you've been using on your CRT
4) Tearing forces you to use VSync

Conclusion:
There really is input lag, but it's not nearly as much as people are trying to show. It is only together with the panel's latency that is gets pronounced vs the CRT which does not have any of these two categories. BTW, SED will show the same since they are digital as well. Like I said, it's the time the DSP requires to process the pixel, send the data to the panel and the panel actually outputs the voltage that turns the crystal. This can only be reduced by using faster digital components in the displays.

Graphich cards handle DVI output differently as the analog output. Some lag could originate there.
Resolution is much higher dropping your FPS in your game (1920x1200 vs 1600x1200 = 1.2 times the pixels = 20% less FPS). On top of that, you played your gfx demanding games at 1280x960 or even lower further raising the FPS difference. To complicate things further, VSync is suddenly on which never was before possibly halving your frame rate.

I believe I have shown that the actual input lag that so many people complain about is too small to be recognized by a human even subconsciously. Only together with panel latency does it become noticeable, but again only on subconscious level. What people are actually complaining about in regard to these displays is their resolution. They simply don't have the gfx cards that can drive the displays equally well as they drove their CRTs. FPS drop introducing another x ms of latency which in the end will sum up to some 50ms vs the CRT they owned before. This is actual 50ms we're talking about! So _YES_ it does matter! And _NO_ it's not because of the input lag.

Hope this was an acceptable explanation

Jure

Sorry, double edit: How come TomsHW only measures 20ms latency for a display that's supposed to have another 40ms lag? I need to look a bit deeper into their latency measuring methodology. This looks more and more like a gfx card problem, not the actual display problem. Dual link DVI maybe (not that these need one though, but maybe it is used anyway)?

 

[darXoul]

Originally posted by: Madellga

What a salad!! You're mixing all lags together and they mean different things for gaming. Network lag is accumulative, meaning you add your lag to the players on the server. That makes gameplay difficult. And we are talking here 150ms to 300ms, which anyone normal call tell.

This ditto monitor lag people talk about cannot be "perceived" by us. I'm not talking about fast or slow LCD panels.

The only person who can work in 50ms timeframe is The Flash

Yes, they do mean different things (shift: input - display and shift: PC - server) but they add up in a way, screwing up your efficiency.

150-300 ms is... OMG, help me find a word 50-100 ms total lag would already be on the verge.

What I can tell you is that I can easily distinguish between 20 and 50 ms of lag. Believe it or not.

Velis, I also thought about the insufficient GPU power. However, I'v also seen input lag claims of people who had top notch hardware. Oh well, doesn't matter for me anymore. I'm not getting a PVA display anyway

 

[xtknight]

Use my program here (uses x86 RDTSC clock for accuracy). It's as accurate as you can get so millisecond measurements should be more correct. Even showing one out of every 300000 values printed is unreadable if that gives you an idea of accuracy.

http://forums.anandtech.com/messageview...atid=31&threadid=1798513&enterthread=y

Run both CRT and LCD at 60 Hz because the LCD's DSP may do refresh rate downscaling/interpolation at >60 Hz.

 

[Madellga]

Originally posted by: darXoul

Originally posted by: Madellga

What a salad!! You're mixing all lags together and they mean different things for gaming. Network lag is accumulative, meaning you add your lag to the players on the server. That makes gameplay difficult. And we are talking here 150ms to 300ms, which anyone normal call tell.

This ditto monitor lag people talk about cannot be "perceived" by us. I'm not talking about fast or slow LCD panels.

The only person who can work in 50ms timeframe is The Flash

Yes, they do mean different things (shift: input - display and shift: PC - server) but they add up in a way, screwing up your efficiency.

150-300 ms is... OMG, help me find a word 50-100 ms total lag would already be on the verge.

What I can tell you is that I can easily distinguish between 20 and 50 ms of lag. Believe it or not.

Velis, I also thought about the insufficient GPU power. However, I'v also seen input lag claims of people who had top notch hardware. Oh well, doesn't matter for me anymore. I'm not getting a PVA display anyway

Talking about game lag, here is some story....

I quit playing WoW in February. One thing was motivation, got bored. Other thing was time, consuming it too much.

But the killer was the lag I had. When the server was empty (like Monday 06:00AM), I usually got 100-150ms. During normal times, 300ms was the rule. And Saturday evenings, OMG, 900ms to 3000ms. We are talking here about an european server.

Things became worse after November. Friends from different servers living in different countries had same issues. My Guild used to call Orgrimmar "Lagrimmar". It would take several seconds to open an auction or the mailbox. PvP was impossible. I was being killed without knowing the reason or even seing the attacker.

I wrote to Blizzard support, explaining the problem, listing my hardware/software and even provided a trace file from my connection showing the issue was at Blizzard, not my ISP. After 1 week they wrote back asking me for the trace file and information about the problem. What a joke!

I went to the account admin and closed it. And they charge the monthly fee.....

PS: Other online games work fine here (Guild Wars, BF2, etc etc).

 

[Heartbreaker]

I owned a 2405 for a week and I would not recommend it. Just because someone doesn't notice an issue and loves the monitor doesn't mean some monitors are good and some are bad, it just means some people don't notice small details. I researched and tested heavily. Here are my 2405 observations: These are all backed by data online.

The good:

It has amazing size, beauty, and sharpness. A godly sized beauty of a monitor. Colours looked amazing. Mind blowing beautiful.

The bad:

Lag: It felt a bit slow, like my mouse was heavy initially, so I researched, found a a lot on lag. Tested by stradling a window half on the CRT half on the LCD, move it. You can see the LCD play follow the leader. But if you are not a competetive FPS player, you can adapt. After a day or so I didn't notice anymore. After a week I went back to CRT. It felt like my mouse was on steroids for the first few minutes it was almost telepathic is response. I don't even play FPS games so I didn't really care about this. It had nothing to do with ditching it.

Brightness: Brightest monitor on the market. Too bright even at zero backlight setting, for me in my old school dimly lit computer room (160W total lighting in big room). It hurt my eyes to use it until I also toned it down via the graphics drivers which started to negatively impact image quality. This did play a part.

The Ugly:

Terrible viewing angle anomolies. Preface this by saying apparently these don't bother most people, but they are there, I verified it on 24" samsung screen as well, they also seem worse in a dim environment with the settings adjusted to compensate. PVA panels change dark tone with small viewing angles, combine that with a big wide panel and you are always at some angle if you sit reasonably close. I only played two old games: Total Annihilation where I noticed the start screens undergoing tone shift if I move my head two inches. NeverWinter Nights were they shadowy darkness would shift tone at small movements. Not only this but eye separation produces different angles which produced glare/edge effects as well. It drove me nuts.So I threw up a test pattern to see what was going on:
http://i.pbase.com/o4/04/606404/1/57902216.clip5.png
Found out the 5%-30% range is disproportionally affected by small angular changes. This factored heavily into the deciscion to get rid of this monitor.

I would say go for a IPS based monitor, to limit view angle issues, like the 23" HP, which apparently also has better backlight control. Possibly less input lag as well.

I am deciding between trying the Dell 2007FP (20" 4:3, IPS panel) or getting a new CRT.

 

[Markbnj]

I have no issue with the idea that some people perceive a given monitor one way, and others another way. I don't agree that there is any conclusive data that these effects exist. I don't see any significant changes on that test pattern when shifting my viewing angle by moderate amounts, for example, and I definitely do not experience any mouse lag. Certainly an LCD redraws slower than a CRT; don't think that is in dispute.

It definitely is bright as all get out. But then so are most LCDs. I just bought a Sceptre 37" 1080p panel for my living room, and you could watch that thing in broad daylight on a tropical beach.

Anyway, if you're considering this monitor, or any other, best thing is to do as the above poster did and check it out for yourself.