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Does Your LCD Play Catch-Up To Your Mouse?
Dishes of Ryan writes "I fell in love with the idea of an LCD monitor, so I ended up buying a nice, shiny Dell 2001FP. However, nowhere, and I mean *nowhere* did I read about LCDs having an input lag on them. For instance, if I scoot the mouse across the screen, there is a noticeable delay between when I move the mouse and when the cursor moves. To prove it to people, made a video showing exactly what I mean. You can almost forget being king of the hill on twitch FPS games like Unreal Tournament. Are there any other Slashdotters out there that are as annoyed as I am? What did you do?"
No offense, but you need to get another monitor. I notice no "lag" between my iBook and CRTs, nor do I notice any lag on my new 17" KDS for my desktop. Having developed a few video games and GUIs, I have a fairly well trained eye. I can see the problem in the video, but I see no such problem on my systems.
Conclusion? Dell buys parts from the lowest bidder. Ergo, they are the lowest quality. Therefore, you need a better monitor.
Sorry.
Javascript + Nintendo DSi = DSiCade
I wonder if it's the display that's lagging, or the video drivers? The last time I recall seeing an LCD display "lag" was back before the days of TFT screens, where your mouse would "submarine". (disappear while it was on the move)
I work for the Department of Redundancy Department.
I've built countless systems with various high and low end LCD screens with no such lag. The worst screen I've encountered had the typical old-generation ghosting, but I've never seen input lag.
I'd recommend popping in Knoppix and see how it works. It will probably pick an open driver made for your graphics card family. You say this happens with the mouse, what about typing?
I've had zero problems on both of my laptops and every LCD I've ever used. Something's screwy with your hardware. It's rather sad that Slashdot posted this as a front pager...
What did you do?
I posted a 800K movie of it on Slashdot so I could suck up all the Internet's available bandwidth and make everyone else's game run at the same fps as mine. =)
That monitor is actually a BenQ monitor with Dell's name on it. It's a great monitor, and has a 16ms response time, so it shouldn't lag at all in normal use. You should try video drivers or maybe even the mouse itself. There simply is no reason a good monitor such as that one (congratulations on your purchase. That's the best cost to performance monitor out right now.) should show lag in a normal situation. I have used a 25ms LCD, and it doesn't lag in normal use. Call Dell after if driver's don't work.
It's the buffering in the driver.
Flat Panels *will* ghost and blur, however they do not lag.
What causes this is buffering of execution commands in the drivers, which makes some games at certain resolutions lag really really bad on input.
Change drivers, and it will usually go away.
I've used lots of LCDs, including plenty of DELL LCDs. The LCDs we've used at work were faded, and the colors looked awful after a copule of years. but I've never never seen any kind of lag like this in any kind of monitor.
My guess is that there is something wrong with the video drivers, or the mouse drivers, or some other part of his computer that's causing these problems.
I can't see the vid because the file is apperantly slashdotted.
autopr0n is like, down and stuff.
rtfa?
the lag is not coming from that.
hell, just read the damn blurb.
here's for the stubborn people:
two monitors, fed from the same computer. other one is some flatty dell and the other one is a crt. now, the movie is about doing something with the mouse that affects both screens, and happens at the same time in the video cards memory, and having observable(with a vid cam..) lag between the two monitors.
world was created 5 seconds before this post as it is.
Easy. Slashdot editors are idiots who don't care a wit for the content on the site. I mean really, this site could have so much potential, but it's really been squandered by the creators. Average people who don't want to cede control to people who could actualy do a good job.
/rant.
autopr0n is like, down and stuff.
Never, under any circumstances base buying decisions off of reviews from Newegg. Half the reviewers state they're first time system builders with no real idea of what there doing. The other half try to sound like they know what they're talking about, but obviously have no clue, or are just flat out lieing. Then you have the problem that newegg removes the reviews that are less than pleasant. Your best bet is to read a site that focuses on reviews and sells no hardware. Maybe Slashdot could start a hardware review section and do some unbiased hard journalism!
--fetch daddy's blue fright wig, i must be handsome when i release my rage
Since when was /. an online PC troubleshooting forum? Any doofus knows LCD screen don't suffer from "lag" -- why doesn't he call Dell or ask on a newsgroup, not take out an article on the front page of Slashdot???
http://www.vtnetworks.net/CrtLcdComparo.wmv
DoR> Um, my mouse lags on my Dell LCD.
DoR> How's that gonna' help?
You might get even better results if you tried using the video card's outputs.
This post written under Gentoo-linux with an SCO IP license.
'nuff said.
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I'll have to say BS on this. My suggestion is to borrow a second CRT and hook it up the same way. Most likely the lag will still be there. I have no idea what OS as the video is down. My answer is to upgrade the video drivers and check for some stupid setting being messed up.
I'll join the chorus of people saying "no". Either it's a problem somewhere else in your system, or a really crappy LCD.
:-), which has made a complete convert out of me.
... "we're stylish and we're not going to let you forget it!").
I used to not like LCD monitors, especially the kind that use the analogue video out, but at work I got an NEC MultiSync LCD 1760v (17", 1280x1024 -- I know, yesterday's news, but a great step up for me
Not only does it have far better contrast and brightness than other LCD monitors I've used, but it has no ghosting of any kind, and tracks the analogue video output of my computer flawlessly. Even the industrial design is great, much better than typical "we've got a really expensive CAD system and no design sense whatsoever" designs, and I'd say on par with Apple's wonderful creations (without Apple's tendency to be a bit poncy
The display gamma seems to be much different than my old CRT, so it did take a bunch of adjustment to get pictures looking the same.
Anyway, 3 thumbs up for the 1760V from me (this model is a few years old I think).
We live, as we dream -- alone....
I have never seen lag attributable to a USB mouse.
In face, USB mice typically lag LESS than PS/2 mice because they update their position far more often.
The option in games isn't "REDUCE MOUSE LAG", it's "SMOOTH MOUSE", which is specifically designed around the problem of mice with low update rates (namely PS/2 mice, and in some cases REALLY crappy USB mice can have a slower update rate than a PS/2 mouse but it's RARE.)
retrorocket.o not found, launch anyway?
Hey, will even throw in shipping. :)
I prefer the "u" in honour as it seems to be missing these days.
UT2004 specifically has two options:
1: Smooth Mouse
2: Reduce Mouse Lag
The normal usage of USB mice should be fine without lag, but when the computer is using all of its resources, USB doesn't get updated as quickly as it should, thus causing the mouse lag.
PS/2 mice have better access to Windows resources and the mouse position gets updated properly and on time.
I am defenseless. Use your button. Mod me down with all of your hatred.
the original quote is from John Glenn, when he was asked what it felt like sitting atop the rocket, ready to launch:
"I felt about as good as anybody would, sitting in a capsule on top of a rocket that were both built by the lowest bidder." (Senator John Glenn, Colonel USMC, Retired)
Rockhound is applying the sincerest form of flattery.
If you forget about the future, the future will forget about you.
Now you've got me curious... No offense to the submitter, but this is obviously an isolated problem. Asking the average wage slave techie down at Best Buy could have confirmed this. Infact, nearly everybody on Slashdot has confirmed it to one degree or another. Soooo... Why is this frontpage news again? Will Slashdot start answering my unique one-shot hard drive problems now too? Hi, my name is Ed and my HDD is making an odd 'kerchunk' sound when it starts up. Have any other Slashdot users noticed this with their HDDs????? Why not? Let's convert the front page to miscellaneous hardware bug reports... Or not?
I'd submit to you that this question should have been handed off to any number of the flatscreen FAQ sites out there, especially given how unique the problem is. We're not exactly talking about ipod batteries here.
You need a FREE iPod Nano
Dude, no human has reflexes like that.
You're either:
a) Not human
b) Jedi
c) Stoned/Drunk
Go become a fighter pilot or something like that.
-- If you try to fail and succeed, which have you done? - Uli's moose
For some reason, all of my games ran like crap after picking up the display... Game after game simply ran like a slug after the LCD was added to the mix and I couldn't figure out what the problem was.
I finally noticed that if I took my hand off the mouse, things ran smoother.. After some trial and error I discovered my first generation optical Intellimouse Explorer didn't like the USB hub on the Dell monitor (I plugged it into the 2001FP's USB ports to add some slack on the mouse cable). While the problems were not readily apparent on the 2D apps, they were incredibly apparent in the games.
So after moving the mouse back to the PC's main USB ports, everything improved dramatically. It gave me an excuse to pick up that new fancy Logitech laser deal.
www.lonseidman.com
You can probably do the same thing with Gimp, but it's not immediately obvious to me how to do it.
Since everyone is skeptical, I would like to chime in and say that I'm having the exact same problem (same Dell monitor, too). Perhaps the addition of my specs will shed some light on the culprit.
So far I've tried two different video card setups (both MacOS X on a dual 1GHz g4 power mac). The first was the GeForce 4MX card that shipped with the computer. I was using analog output to analog monitor input. Thinking the lag could be the result of analog to digital conversion, I purchased the ATI Radeon 9000 with digital output.
I'm currently using the digital video output to digital monitor input. The problem is still there. Both cards are AGP, and I never experienced a lag before buying the Dell.
Hopefully this helps. If I've left out something important, let me know.
Sorry, that's my keylogger that's causing the lag; it's writing all your keyboard inputs directly to my web server instead of logging and uploading the log, and that's slowing down your system.
Please type "updateme" on your keyboard, and that will tell the keylogger to automatically update itself. Once it's updated, you shouldn't notice any lag at all.
-- If god wanted me to have a sig, he'd have given me a sense of humor.
This was a big problem with passive matrix screens. I've had old-school (black and white) PowerBooks that did this, and my first ThinkPad (365X) did this too.
However, I have *zero* problems with this on any active-matrix screens I've ever worked with. ThinkPad 600E: lovely, crisp screen, no lag, cursor right there where you want it. PowerBook G3: the most awesome LCD I've ever seen this side of a Cinema Display. I even have a cheapy Taiwanese 15" LCD panel, Envision is the brand, and it's splendid. No lag, no lost cursors, nice and crisp.
That sort of thing shouldn't happen with a modern TFT active matrix screen. There is something very wrong with it.
Knowledge is power. Knowledge shared is power multiplied.
I have owned several Dell displays and have had no problems. I HAVE had lot of problems with "mice" over the years. In fact I had to replace my first generation Intellimouse optical wireless as it just did not work well with my new system. I would put the blame on the mouse, more than the LCD screen. It's amazing that this obviously minor problem has gotten so much attention: I.E. try another mouse before filming yourself and complaining to the entire internet community. Heck, I was having problems all around till I unplugged my bluetooth adapter.
"Jeremy, you need to get to an internet cafe and cut and paste some appropriate sentiments about me from the world wide
For Windows users, Windows will easily bring up such an image on the desktop; it's under Display Properties, Background, Pattern, 50% Gray, (at least under Win2k).
Slashdot as we know it would cease to exist!
Slashdot - where else you can be utterly wrong and get hailed as informative and insightful? Yeah, yeah - I meant besides FOX news.
That's my guess. A lot of things happen during the vertical blanking interval or on some other similar periodic interrupt. In most OSes, this includes screen updates and mouse pointer redraws. This could be anything from a buggy driver to an IRQ conflict, or possibly even a bad trace on the motherboard (though the latter isn't anywhere near as likely).
If an OS reinstall doesn't solve the problem, there's probably something weird going on in the BIOS settings and/or the motherboard itself. Pull the BIOS battery for an hour. Try again. If that doesn't work... is your clock running slowly, too? If so, buy a new computer. If not... buy a new computer. EIther way. :-p
<rant>And speaking of IRQ conflicts... why hasn't any motherboard manufacturer broken with tradition and actually added enough distinctly addressable interrupt lines? I mean, the Mac has supported 64+ interrupts on its interrupt controller since 1995. Does it really take a decade of engineering to figure out how to cascade two interrupt controllers and add a driver to support it? Sheesh!</rant>
Sigh. Another victim of a 2004 computer crammed into a 1981 architecture....
120 character sigs suck. Make it 250.
The following sequence seems to do the trick w/ GIMP 1.2.x:
That should get you a checkerboard pattern on a 1-pixel increment. I haven't seen what this does for an LCD monitor's ability to fine tune an analog signal (since I don't own such a display), but I think it's the pattern you're using. It's the same fill pattern the old monochrome Macs used for their desktops. LOTS of edges to sync on, on every line! :-)
--JoeProgram Intellivision!
I submit articles about the chips in "missile defense" systems being faulty, and they're shelved. Someone incorrectly configures their cheap monitor and it makes front page? WTF?
Here's the amazing answer: If it sucks, take it back.
Shit.
I just don't get it. This is the most basic thing you check with the LCD display.
Some people out there still look for higher vertical refresh rate at LCD. *sigh*
Common features:
Diagonal
Color quality/reliablity [1]
GFX input capablity. (VGA/DVI/S-Video etc)
No missing (dark) pixels.
Important with CRT:
Maximum resolution
Maximum Vertical refresh rate at resolution you most frequently use.[2]
Image sharpness
Black pitch [3]
Flatscreen/Trinitron(cyllinder)/Sphere screen.
Important with LCD:
Default (non-interpolated) resolution [4]
<b>Pixel switch-on time</b> (display lag)
Pixel switch-off time (ghosts)
Vieving polarization angle[5]
Maximum brightness
Working temperature range
backlight LED lifetime [6]
[1] These ARE different. LCDs have sugar-sweet beautiful colors, that can't be repeated in print, that's why LCDs are the worst choice for a graphician, while your average end user will enjoy the more-than-lifelike graphics immensely
[2] On CRT image at 25HZ hurts your eyes badly. On LCD you can freely read books at 25HZ, the refresh rate doesn't mean cycles between switching the image on and off, but between changes to constant content.
[3] Is black really black or just a shade of grey?
[4] LCDs have one fixed resolution at which they look great, all the other resolutions suck as computer output pixels don't match display pixels.
[5] If you don't look straight ahead at the screen, some colors just go dark on some screens.
[6] LCD doesn't shine. LCD switches half-transparent pixels on and off, masking the white backlight LEDs off. Without backlight you'll see hardly anything. It's the backlight that eats up most of your batteries too. And it's the LEDs that die first if the screen doesn't get broken/scratched etc first.
Anagram("United States of America") == "Dine out, taste a Mac, fries"
It isn't valid in C89 (ANSI C), because main must either take no parameters, or take one of type (int) and one of type (char **). However, ANSI C compilers are allowed to silently compile this program (and perhaps fail at runtime).
Calling a function without prototype assumes the function was declared as:
int f();
(NOT int f(...) as another poster mentioned, this isn't even a valid declaration as there must be at least one non-variadic parameter)
which means that the number and type of the parameters are not yet known, and it is undefined behaviour if any call to f doesn't match[%] the actual definition of f(), wherever that might be.
Calling a variadic function without prototype is specifically undefined behaviour (for example, many compilers use a different calling convention for variadic functions to non-variadic functions, as another poster mentioned).
However if the convention is the same (eg. gcc on IA32) then it's likely to work correctly. (But still non-portable, obviously).
[%] The number of arguments must be the same, and they must have the same types after the default argument promotions: float->double, and (integer-type-smaller-than-int)->int, (other-types)->(stay-the-same)
I'm at work right now, and I have two Dell 2001FPs running dual-monitor. I was able to replicate *exactly* what's shown in the video--when dragging a window that spans both displays, the window moves faster on the primary display (on the left) than on the secondary display (on the right).
It's not the monitor. It's not CRT vs. LCD. It looks like that's the way Windows deals with multi-monitors.
I humbly suggest that the article submitter swap his displays and use the LCD as primary, and see if the CRT then displays the lag. Bet you dollars to donuts that it will.
First of all, thank you, everybody, for taking a look at this. I received a characteristically Slashdotty wealth of "you're an idiot" replies, and a good number of "I didn't read the full article and/or watch the video so I'm jumping to conclusions" replies as well. =) Those of you that read the article and offered your genuine insight, thank you.
It's all fine, though. I'd like to answer a few randomly culled questions here, and also summarize what I've found based on all the feedback so other potential LCD owners can get a better feel for what they're up against.
The overall summary, which you may or may not agree with is: Most LCDs are laggier than CRTs (I'd be jumped in an alley if I went as far as to say *all* LCDs are, but I try to avoid sweeping generalizations). Do your own tests, and come to your own conclusions. If you're a gamer, be careful. And lastly, my Dell 2001FP may in fact be one of the laggiest LCDs in existence, *or* I just received a defective unit.
Thanks again, everybody, for the replies. I hope this helps some people. I know that I at least saw one person in the comments that learned something new, although it was, in fact, for something unrelated to the immediate post. =)
If you're running games at the native resolution of your display (1600x1200), the most probable reason for the lag you're seeing is that your video card simply can't keep up. It takes a pretty beefy video card to push that many pixels per frame. Try cutting the resolution to 800x600 and see if your results improve.
Another thing to try would be toggling the "vertical sync" option in your video card's advanced properties. This option specifies whether your video card synchronizes frames with the monitor's refresh. Your CRT probably refreshed at 100Hz, and your LCD is probably just 60Hz, so vertical sync could be slowing you down even if you haven't increased your display resolution.
IIRC, the infamous "code to explode a monitor" trick involved setting monitors to refresh rates that the monitor could not handle, causing the monitor to burn out or, in extreme cases, explode. It was a small subset of the monitors, but it was one of those things that made it into popular lore. I belive they even referenced it in Cryptonomicon, having a character who supposed had his face mangled by an exploding monitor triggered by a virus of some sort.
This sig has absolutely no significance and serves only to take up screen space and waste the time of the reader.
It turned out his keyboard had a faulty K key, and the K was not appearing on his screen either.
And thus the GNOME project was born...
So, of course, it got opened.
Specifically, I was curious about the fact that I was able to plug the thing directly into my (very) old graphics card which was built before there were such things as desk top flat screens, and actually have it work.
The signal being output by a graphics card is designed to be understandable by the average computer CRT. --Which, (when I've opened those in the past), don't contain a whole lot of extra electronics beyond on-off switches and very basic control systems. That is, with a standard CRT, the signal from the graphics card in my compy pretty much feeds directly into the electron gun and magnetics control system of the CRT monitor with very little intermediary electronics in between. All the really clever electronics is done by the graphics card back in the tower case.
So. .
Since TFT monitors work on a radically different principal than CRT technology, this means that the output signal from my old graphics card, (which I'm guessing is analog), must be translated into a very different type of signal which can be interpreted by the TFT screen electronics, which I am guessing is a digital signal.
This would mean. .
The original image dreamed up by the computer is digital, then converted to analog by the graphics card so that the CRT can apply it, and then because there is no CRT, it is converted back again into a digital signal for the TFT.
Oh yeah. Now that's efficiency!
And it worried me, actually. When I was shopping for my flatscreen, I was bugging sales people, "So are you SURE I don't need some kind of proprietary graphics card to run this thing? If that's the case, then I'm no going to get a flatscreen. I need a GOOD graphics card. Not some hunk of standardized junk made by the flatscreen manufacturer!"
The sales guys always just shook their heads. "No sir. You just plug it in."
"Oh. .
But what do you know? I plugged it in, and no problem. It worked like a charm. So, like I said, I had to open it up.
When unscrewed and pulled apart, voila! Unlike the guts of a standard CRT, there before me inisde the TFT was a whole LOT of extra circuit board and chip set confusion sitting between the monitor cable plug and the flexi-cable which feeds into the actual screen system. So there is some serious signal in interpretation going on! --And none of it, I imagine, would be industry standard; each CRT to TFT signal converter is probably designed and built by whoever happens to be making the flatscreen. This extra engineering necessity provides a whole pile of room to make bad decisions and crappy electronics.
My guess is that this is where the lag you are experiencing is coming from.
For my part, I was fortunate in that Samsung did the job well. I ended up with a system which works invisibly, with no perceivable lag between any input and screen output. Perhaps you can sell your screen off on Ebay and get a better monitor.
Of course, the problem may be something else entirely, but that's my two cents. Hope it helped!
-FL