Dell 2405fpw VS. Samsung 243T - Dell has Lag!!

gustep12

n00b
Joined
Nov 21, 2004
Messages
31
Sample Photo Showing 2405fpw (left) and 243T (right) simultaneously:
2405fpw243t32ng.jpg


Motion blur of 243T and 2405fpw photographed & compared:
2405fpw243tblur6lp.jpg


Gamagic test pattern:
2405fpw243tcalib9ja.jpg



I don't have much time or much webspace, but I did have the money to buy the Samsung 243T six months ago for $1750, and the Dell 2405fpw three days ago for $970, both new in box on Ebay. I hooked them both up as cloned displays to my Radeon AIW 9600 XT and started evaluating... I even took a lot of pictures, but I might have to redo that - shooting at short shutter times ~ 1/125 sec, low ISO (for little noise), all at screen light levels is pretty challenging. Add in manual white balance, and most importantly, curvature of depth of field combined with these huge areas, and soon you can't tell whether the soft-focus look comes from motion blur, lack of megapixels in your camera, or incorrect focus (curvature of field). That's why I have to test some more. However, here is what I can tell you:


Motion blur (a.k.a. ghosting):
Ghosting is clearly reduced over the 243T, but the "overdrive" technology used to achieve that brings its own set of strange artifacts, for example where the 243T might leave a motion blur trail, the 2405fpw tends to overcompensate, leaving a "negative" motion blur trail of opposite color. Still, overall motion blur is reduced and fast-moving objects tend to consistently look sharper and more contrasty on the 2405fpw, but nevertheless the "negative motion blur" artifacts are visible if you look for them hard enough, e.g. with a scrolling text (in Windows 2000, try the Marquee screensaver, dark grey background, fuchsia colored lettering, speed set 10 clicks to the right from "slowest").


LAG:
Strangely enough, the 2405fpw has about 50ms (+/- 20ms, difficult to measure) signal delay over the 243T. This showed up when several photos, which show both monitors side-by-side at the same instance, showed slightly different screens. For example, in UT2k4 a green plasma bolt from the link gun would consistently be further along its flight path in the 243T than in the 2405fpw. To make sure it's not the graphics card I switched the VGA cables and it still was the 2405fpw that lagged behind. Oh well... DSP processing has entered the realm of computer screens, I guess. In trying to estimate the delay I photographed fast-counting loading screens etc., and the difference in % loaded combined with the total time to load gave me that 20-50 ms estimate. In terms of gaming performance, this might mean that on the 2405fpw you're up to 3 frames behind.

Does that matter? I don't know... on one hand I don't think that even 50ms really matter, but on the other hand, if you look at the scrolling text offset difference in my "sample photo explained"... it just ocurred to me that not only the text, but also a jumping enemy will be displayed in a different location by these two monitors. So if you're a quick sharpshooter in Unreal Tournament 2004, the 2405fpw could mess up your aim. Only one of these two monitors can show the true position, and it's likely the faster one, meaning the Samsung 243T. With the 2405fpw, while you think you're right on, you actually keep aiming a bit *behind* your opponent by up to a full body's width, if he is far enough away and dodging fast enough sideways. That's because when you have him in your sight, the player will actually have moved on a bit further already. I'd say that sucks.


Backlight:
Flicker free LCDs? Don't believe all the hype. One one hand, the 2405fpw is clearly brighter and at at 10% matches the 243T at 70%. On the other hand, however, the backlight on the 2405fpw seems to be cheaper made - when aiming a digicam at the 2405fpw, the digicam screen flickers, showing that the 2405fpw screen itself must flicker enough for the digicam's gain compensation to pick up on it. Compared to that, the 243T screen always appeared solid on the digicam's LCD.

I went a bit further and tested this by wriggling a few objects quickly in front of both screens in a darkened room, to see if these objects would leave a bright uniform light streak or a "choppy" one, as the one you would see if you waved your hand under a bad neon light. As it turns out, the 2405fpw chops things up, e.g. flickers slowly and intensely enough to create this effect. No such choppiness could be produced with the illumination provided by (to) the 243T. This confirms my suspicion that the 243T is much better built and has a much faster driven backlight. This is a bit disappointing, because I really start liking the 2405fpw, but I wonder if the slow flickering backlight of the 2405fpw might produce more eyestrain than the 243T, in the long run. That's not something I'm keen on. Unfortunately I have not yet been able to capture this effect on photos (which shutter time...?), but it's there.


Buzzing:
After reading some threads, I learned about the buzzing of the 2405fpw and decided to look into it. I have it, too, it's faint, but noticeable especially by holding an ear up to the frame. I then recorded the buzz with a microphone and analyzed the frequency spectrum in cooledit: It is pretty much a 218Hz square wave buzz. My guess is that the backlight of the 2405fpw is driven at 218Hz, which should pass as "flicker free", but which is still far from what a quality backlight could do in terms of frequency.


Colors & Contrast:
Again, slightly improved on the 2405fpw, especially in highlight detail and black level - but only AFTER I went through a painstaking gamma curve adjustment (Offset1, Offset2, & Gain) in the hidden factory settings menu. For that purpose the "Gamagic" patterns helped a lot (second link in Google). Before I did that, colors looked too intense, and worse, I couldn't get the white balance right across different shades on a gray scale ladder. For example, if I had white-balanced the midtones with the standard "user" RGB color controls, the highlights would be reddish!! In this regard, the Samsung 243T was much better calibrated by the factory. In summary, Dell must have done some calibration (because I also saw much worse settings), but their calibration job must have been marginal.


Those are the most important findings I had. Overall, the Samsung 243T strikes me as a higher quality but older generation product. The 243T has the better design, the sturdier case, a real on-off switch in the back, it's much heavier, it's much better color-calibrated, it has a VESA compatible stand, it doesn't leak light out the back, it's backlight is much more flicker-free (probably a higher frequency), and it displays data about 30ms faster than the 2504fpw. Oh, and before I forget - the Samsung has 3 years warranty. With Dell, it's nearly impossible to find any reference to their warranty policy of a particular product such as the 2405fpw.

On the other hand, the 2405fpw has undeniable advantages such as price, improved contrast (but not by as much as you might think from the specs) & less motion blur, both of which improve the perceived image clarity over the already awesome 243T. It also has a built-in card reader & USB hub, and due to it's lighter weight and better cable guides I would (and did) actually make use of the portrait-pivot function - the 243T has this, too, but it's more difficult to operate. If you calibrate your Dell (ideally in hardware, not with a software ICC profile) and don't mind the light shining out the back case, it makes an even slightly better display, I'd say. Oh, and the 50ms delay - at least now the screen is not ahead of the DSP home theater sound system anymore.



This shows the delay problem once more:
2405fpw243tplasma6oe.jpg
 
Well done... I knew that this overdrive stuff would have problems of its own, and wouldn't magically eliminate ghosting. Boy am I glad to have the IPS panel inside the 2005fpw... Regardless though, the 2405 (and the 243) are still fantastic screens. Yes we all know that the Dells are cheaper made, but that's why they're so much less to buy.
 
Hmm, are you guys sure that delay is caused by overdrive? Do you think all LCDs with overdrive will have this problem? I was going to get a 2405FPW but now I'm not sure anymore :(
 
Just a quick answer to how I see things: The cyan dot trailing the magenta scrolling dashes is with near certainty due to the overdrive technology, but this artifact is rare and difficult to elicit - meaning you won't see such stuff with most other color combinations and in most other situations, like normal gaming etc. Overall, the 2405fpw does make moving images consistently sharper than the 243T.

However, the bothersome 30-50ms delay, which I haven't been able to nail down in terms of ms, that could be due to a variety of reasons.

Possibility A: It's required for overdrive technology, since the display needs to know and analyze the second and third next frame before it can determine the appropriate overdrive signaling strategy to transition over from the current frame to the second next frame. This would mean you find it in all overdrive panels.

Possibility B: The 40ms delay is simply due to the microprocessor inside the display that converts the input (VGA, DVI, S-Video, etc.) into the panel's native signaling. The current GM1601 chip that is used to to that in the 2405fpw seems to be doing a good job overall and is highly sophisticated, but maybe it's taking a bit more time than other chips before it. This would mean that with a different set of input processing electronics this delay could have been eliminated.

Regards,
Sebastian
 
I do a lot of video-editing/converting on 2405, and have to especially careful about sound synch. If there was a problem with the screen delay, I would definitely notice that, esp. if it exceeds 20ms. Frankly, I don't notice the lag, it might that your unit is defective or something. Just my $.02 ;)

To see if you have a problem, run a short video clip (30fps minimum) and see if the sound is slightly ahead of the image (very notieable during dialogue).. if it is, u do have a problem. I don't :D
 
Are you sure this is the 2405FPW lagging.... or is it your crappy second DVI controller that's giving distorted images? :( Have you tried swapping the panels with a different DVI output each time? Frankly, I don't think an ATI 9600XT can handle 2 1920x1200 displays at the same time with equal IQ...
 
In case you didn't know, the graphics card I used has two outputs that can be used for dual display purposes etc. To make sure the second output isn't the reason, I switched the monitors at the outputs, and the result was still lag in the 2405fpw. That confirms it beyond any doubt.

Now here's a tidbit to keep the hopes of 2405fpw fans alive:

It *could* be that this will be better with a DVI output. My card has dual VGA outputs. It would still mean that the 2405fpw has slower VGA input processing than the 243T. However, since the DVI and VGA inputs are processed by the same chip in the 2405fpw, what do you think the chances are that its DVI signal processing is much faster?

I'd be happy to compare the monitors on a Dual-DVI-Out card, but I don't have one, and I also only have one DVI cable. My feeling is I will have sold one of these monitors before I can do that test.

Someone else should therefore compare the signal delay in the 2405fpw and the 243T when using DVI inputs. My guess is that it's still the same result: Lag in the 2405fpw. Still, that's the monitor I might keep after all, but it's sad that it can't be perfect. Another concern of mine is that I might regret giving the 243T and it's super-steady truly flicker free (and non-fatiguing) backlight away. Ergonomics issues are no joking matter.
 
It would be great if someone else would do the same and compare their 2405FPW to any monitor, be it LCD or CRT. That way we could see if it's really the 2405 that is laggy or perhaps gustep12 has a defective monitor or its VGA signal processing is somewhat slower.
 
I think lag might have something to do with video drivers as someone before mentioned there was mouse lag on desktop and a few games and updating the drivers fixed it, I believe it was with an ATI card. Personally, I do not see this lag in any games or movies I've watched on my PC with this monitor. Making a direct switch from a CRT, playing a ton of FPS games as well as DVDs, I think I'd be sensitive to something like that. Are you using the latest video drivers for the card?

Also, I've taken a lot of pictures of the monitor with my digicam and never saw flickering lines, perhaps the VGA refresh rate works differently than DVI?
 
I can't speak for the delay, but having owned several Dell monitors I can easily state that the VGA inputs on their TFTs are seriously lacking compared to their DVI ones. Not only is the colour reproduction, noise and sharpness all seriously effected, but perhaps you've just proved that timing is too.

It might also be that the flickering you've caught onscreen could also be a side effect of using the DB15 connection. I tried using my canon camera's viewfinder to replicate it and found that the picture did flicker at first, but eventually the shutter adjusted and the flicker stopped. It took a lot longer to re-adjust for the 2405, however, than it did for my other tft (Samsung 172V).
 
Give the Marquee Screensaver a try as I have described.

JonDo[H] said:
I tried using my canon camera's viewfinder to replicate it and found that the picture did flicker at first, but eventually the shutter adjusted and the flicker stopped. It took a lot longer to re-adjust for the 2405, however, than it did for my other tft (Samsung 172V).

hey Jon,

But that's what I mean. This flickering is not at all present on my Samsung panel, and depending on the camera, you only see that flickering when the camera goes to "real time / high gain" to find out the brightness.
 
peacetilence said:
I think lag might have something to do with video drivers as someone before mentioned there was mouse lag on desktop and a few games and updating the drivers fixed it, I believe it was with an ATI card. Personally, I do not see this lag in any games or movies I've watched on my PC with this monitor. Making a direct switch from a CRT, playing a ton of FPS games as well as DVDs, I think I'd be sensitive to something like that. Are you using the latest video drivers for the card?

Also, I've taken a lot of pictures of the monitor with my digicam and never saw flickering lines, perhaps the VGA refresh rate works differently than DVI?

Lag? You mean the 50ms lag I have described? So why, if I don't touch the card but just switch which port the monitors are hooked up to, it's still the 2405fpw that lags?

If you mean the type of ghosting that the 2405fpw exhibits, just try the Marquee screensaver. It's an easy test.
 
Yes, lag or delay as you've said. The ghosting or blurring during fast movements doesn't bother me but I haven't noticed any delay in movement. When you make slight movements with your mouse on desktop is there a delay? Mine appears to correspond instantly. As far as the difference between the 2405 and the other monitor it could be that the timings are different and or more adaptable iwith different drivers.
 
peacetilence said:
Yes, lag or delay as you've said. The ghosting or blurring during fast movements doesn't bother me but I haven't noticed any delay in movement. When you make slight movements with your mouse on desktop is there a delay? Mine appears to correspond instantly. As far as the difference between the 2405 and the other monitor it could be that the timings are different and or more adaptable iwith different drivers.

Well, when I move the mouse it seems to be moving instantly on my 2405fpw, but maybe 40ms delay is not directly noticeable. It could be that a 40ms delay is small enough that in order to detect it, you indeed need to photograph and compare fast-moving screens that are simultaneously sent to two different monitors...

I believe the 2405fpw does have this brief delay, but it doesn't bother me enough to give up on this monitor.
 
Hey gustep,

I'll give that marquee screensaver a try when I get home later. You should really test the Dell using its DVI connection if you can though, before casting judgement on the quality of its screen lag and ghosting. It's said in every single Dell TFT review that their VGA quality is totally naff.
 
JonDo[H] said:
You should really test the Dell using its DVI connection if you can though, before casting judgement on the quality of its screen lag and ghosting. It's said in every single Dell TFT review that their VGA quality is totally naff.
I don't remember anyone saying their screen actually lags when connected via analog. I'm interested in this too. Someone else should post a photo of their 2405FPW and any other LCD while playing a game or displaying scrolling text. It does make sense that overdrive may need to know the second and third next frame before displaying it. If that's true, although overdrive panels will have less blurring they will be less responsive.
 
Who the hell cares if it's VGA cable quality sucks? No one should be running this monitor in VGA mode. If you can afford this monitor, you can afford a video card that has DVI.
 
It doesn't sound too biased to me... regardless, while VGA isn't quite as nice as DVI with these Dell screens, it's by no means a HUGE degredation of quality either.
 
With big props to Google, I finally found some evidence of a problem I've been experiencing since Friday since I bought my 2405FPW.

That damn lag thing pissed me off.

I can reproduce it on DVI and VGA - on a pair of nVidia cards in different machines and an ATI. Compared with my Sony G520, Samsung 191T and 172X and my Dell 8200's internal panel, the 2405 is noticably behind in response. The image may not blur however I was under the impression that response time took the image processing into account!!!!

This panel goes back to Dell tomorrow when I call them up and politely ask for a refund. It is for the tip. The mouse lag bugs the hell out of me.

No photos as I don't have a currently working digicam. But a heads-up that the problem is very real and does exist (I have revision A01 for the record).
 
I noticed the same lag when cloning my G520P CRT and 2001FP so I doubt it has to do with overdrive (6800 GT videocard), it was easily noticable even when just opening and closing windows, the LCD would always be slightly behind what the CRT was displaying.

When cloning my Sony CRT HDTV and G520P CRT there was no noticable lag between the displays so it definately had something to do with the LCD itself.
 
gustep wrote:

<<One one hand, the 2405fpw is clearly brighter and at at 10% matches the 243T at 70%. On the other hand, however, the backlight on the 2405fpw seems to be cheaper made - when aiming a digicam at the 2405fpw, the digicam screen flickers, showing that the 2405fpw screen itself must flicker enough for the digicam's gain compensation to pick up on it. Compared to that, the 243T screen always appeared solid on the digicam's LCD.>>

Maybe this is why the 2405 bothers me so much. Maybe I'm picking up the screen flicker even though I'm not consciously aware of it.
 
Get Post gustep12. Now I'm glad I got the smaller Dell 2005. I thought the bigger Dell would cause me visual problems because of its size.
 
Dell collected the panel a week ago and I await my full refund. Dell were cooperative once I stated that the panel was not performing in accordance with advertised specifications. They are paying the shipping for its return, too.

Nice to see that they're willing to cover the costs here. I won't hesitate to buy another panel once they fix the issues (although I might buy an HP as I hear the HP panels are fine).
 
Lag is in your mind IMO, people are just trying to find excuses to put down this monitor.

Or it could be a fault with your unit.
 
I knew this when I bought it. it was in the reviews. Got bad ratings for video playback and gaming. Suits me fine for my graphic design needs. Excellent color rendition.
 
If the lag was due to the monitor you'd see it in single AND dual configs, as some of you report seeing it only when using dual-display setup suggests the problem lies with the videocard itself and not the monitor (why would a monitor behave differently when using 1 or 2 displays? as far as it is concerned it still displays only what the video card sends it and is not "aware" of a 2nd display hooked up, that's the video card's problem.) Seems like a lot of BS is floating around about this lag issue, and I personally don't believe any of it is the monitor's fault (I've never seen it personally in either single or dual configurations.)
 
I immediately noticed it in a single monitor configuration, the dual config only validated it.
 
Go4hunter said:
Get Post gustep12. Now I'm glad I got the smaller Dell 2005. I thought the bigger Dell would cause me visual problems because of its size.

I have to agree with you there. I've used the 23" Apple Display for a while, and feel like it's almost too much screen. The 20" seems to strike a nicer balance b/w the smaller sub 19" models and the almost too large 24".
 
Armpit said:
If the lag was due to the monitor you'd see it in single AND dual configs, as some of you report seeing it only when using dual-display setup suggests the problem lies with the videocard itself and not the monitor (why would a monitor behave differently when using 1 or 2 displays? as far as it is concerned it still displays only what the video card sends it and is not "aware" of a 2nd display hooked up, that's the video card's problem.) Seems like a lot of BS is floating around about this lag issue, and I personally don't believe any of it is the monitor's fault (I've never seen it personally in either single or dual configurations.)

I agree with you, as long as you stick to the guidelines I provided there is no lag.
 
I got a DVI card (Radeon AIW X800 XT), so no more VGA driving the 2405fpw...

I'm still a happy user of my 2405fwp, but the lag is probably the only thing that makes it less than perfect. I've thought about the whole issue a bit more, and here is my conclusion:

RESPONSE TIME is measured on the screen as the time it takes to go from 10% to 90% of the desired change in brightness. This means, the signal is sent to the screen, and the screen output is recorded WHEN IT FINALLY HAPPENS, but NOT SYNCED to the input. There could be an entire second between the time the video card sends out the data and the time the monitor executes the change, and you would still measure the same response time with the method people currently use. Response time really just measures pixel-brightness-changing-speed, it never looks at the following component:

SIGNAL LATENCY can be thought of the time that an electrical input takes from the time it is requested at the "input" to the time it is done being processed digitally and finally executed at the "output". This is always present whenever digital components are involved, for example in digital receivers, LCD screens, Dolby Digital amplifiers, etc, and is often in the range of 30ms.

Analog CRT and analog audio amplifiers respond more or less in "real time" to their inputs (less than 0.05ms), because there is no way of storing and delaying the data - it has to be outputted, or else it is lost (due to "limited bandwidth", but here analog bandwidth is meant, e.g. what frequency can still be reproduced).

On the other hand, digital components like LCDs and dolby digital receivers first need to do some processing on the digital data that they have received. It is buffered, sent through some CPU cycles on the component's DSP, and finally D/A converted to drive the pixel or the actual speaker. All this takes a bit of time. Hence there is always some signal latency, and it seems to be particularly big on the 2405fpw. They should give it faster electronics, i.e. a faster DSP chip to take care of the scaling and input signal execution. I bet this is where some of the comparable but much more expensive 24" LCDs have their competitive edge.

I still have fun with UT2k4 (best game ever) on the 2405fpw, but especially when sniping I just suck - the bolt goes a yard next to where I thought I had aimed, because of the screen signal latency.
 
rofl this thread is just asking for the flames of all the diehard "OMFGGG I LOVE THE 2405 I WANT TO SEX IT WHEN I TAKE IT OUT OF THE BOX" threads
 
Armpit... I, too, thought at the time that it might be the video card's problem, so I tested it: Without touching the computer or video card settings, I switched the monitors at the video card's VGA outlets. This should tell me: Is one of the video card's outlets lagging behind (maybe it's a slave outlet or something), or is it the specific monitor that is lagging behind?

Result: Even when switched, it was still the 2405fpw that lagged the 243T in what it displayed at any instant. Nothing was changed on the display settings on the computer.

So I don't think it had anything to do with the graphic card.




Armpit said:
If the lag was due to the monitor you'd see it in single AND dual configs, as some of you report seeing it only when using dual-display setup suggests the problem lies with the videocard itself and not the monitor (why would a monitor behave differently when using 1 or 2 displays? as far as it is concerned it still displays only what the video card sends it and is not "aware" of a 2nd display hooked up, that's the video card's problem.) Seems like a lot of BS is floating around about this lag issue, and I personally don't believe any of it is the monitor's fault (I've never seen it personally in either single or dual configurations.)
 
there is delay in any one of the DVI/VGA outputs when using dual video output, either its in the driver or a side effect of dual video or the fact that theres two different DVI chips (a SI and the inbuilt nvidia).
 
gustep12 said:
Armpit... I, too, thought at the time that it might be the video card's problem, so I tested it: Without touching the computer or video card settings, I switched the monitors at the video card's VGA outlets. This should tell me: Is one of the video card's outlets lagging behind (maybe it's a slave outlet or something), or is it the specific monitor that is lagging behind?

Result: Even when switched, it was still the 2405fpw that lagged the 243T in what it displayed at any instant. Nothing was changed on the display settings on the computer.

So I don't think it had anything to do with the graphic card.

For some reason the 2405 can have driver problems with stuff and cause that lag. When I first got it I had to download beta drivers for my Razer Diamondback to fix it. I still get lag in the occasional game, altho I can't remember the last time I did. I happens when a game uses a software cursor I beleive.

My old man's logitech lagged in windows also, till I updated the drivers.
 
I have the same problem with the lag on my 2405fwp. I've had my monitor for 4 days now and tried everything from drivers to different computers, nothing works. Although I read in these forums about forcing the refresh rate to 70hz and that did help, although it is still there.
I love everything else about this monitor, but because of the lag I think Im going to return it very soon.
 
max_5 said:
I have the same problem with the lag on my 2405fwp. I've had my monitor for 4 days now and tried everything from drivers to different computers, nothing works. Although I read in these forums about forcing the refresh rate to 70hz and that did help, although it is still there.
I love everything else about this monitor, but because of the lag I think Im going to return it very soon.

Dude 70Hz? your running VGA right and you expected no lag going using 1920 x1200 via the VGA connection after a ADC-->DAC conversion...
 
I just got a Samsung 244t (24" 8ms 1900x1200) and guess what, it has the lag too. This may not be that suprising since it supposively uses the same panel as the 2405, but this isn't just a dell issue. I hooked up a crt in clone mode on the dualhead (7800gt) to compare and the delay is very apparent.

I did just try doing the force refresh rate trick to 100hz, and that definitely seems to help with the mouse sluggishness on the desktop.
 
Sorry this is a bit OT but how do you calibrate using that gamma2point0 thing? Reduce the RGB values until it blends in? I'm trying to calibrate a Samsung 940b and this seems like a good tool to calibrate it with, although I'm confused on how to calibrate with it.
 
Tasc said:
I just got a Samsung 244t (24" 8ms 1900x1200) and guess what, it has the lag too. This may not be that suprising since it supposively uses the same panel as the 2405, but this isn't just a dell issue. I hooked up a crt in clone mode on the dualhead (7800gt) to compare and the delay is very apparent.

I did just try doing the force refresh rate trick to 100hz, and that definitely seems to help with the mouse sluggishness on the desktop.

You are joking right? your telling me the highest end LCD monitor that samsung makes has lag... this isnt anything to do with the PVA technology.
 
Back
Top