Flickering Line when using DVI with NVIDIA Cards

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Thread Starter
Jul 18, 2005
My computer's hardware:
Athlon 64 3200+ on socket 757 ASUS K8V Deluxe
2x 512 Infineon DDR400
Viewsonic VP171 silver 17" 16 ms 1280x1024 LCD
XFX GeForce FX 5900 128mb nonultra
BFG GeForce FX 5900 128mb nonultra
Leadtek GeForce 4 Ti 4600 128mb
Other stuff:
Sound Blaster Audigy 2 NX
Logitech Z340 Speakers
Razer Diamondback, Logitech MX518, Microsoft IntelliMouse Explorer 3.0 mice
Lian-Li PC-6070 Case

My other testing hardware:
An Acer Travelmate 8104 Laptop with a Radeon X700 mobility, Centrino 2.0ghz mobile, and DVI out
A computer identical to my own (my brother's that I built for him)
A friend's computer with an ASUS board and a 2.8ghz processor.
A friend's NEC LCD 19" 1280x1024 25ms refresh.

The problem I am experiencing can rather simply be summed up as a flickering line that is visible in the top row or rows of pixels on my screen. This line has different widths, but usually is visible only as about an inch or two of any given random color. The line is very apparent in any DirectX using game with a black background, such as SWAT4, Doom3, CounterStrike, CounterStrike: Source, among others, and is also visible in some games even without a black background such as WarCraft III/Frozen Throne. It can also be seen in any 3DMark version, 01, 01SE, 03, 05. This problem is ONLY present when using DVI, but using analog obviously has its own slew of concerns and problems and is therefore not to be considered a real solution. Using analog does, however, appear to solve the problem.

I have taken a still image of the line with my digital camera. I had too much trouble getting this picture to work out in the end to make it worth getting another, but I can if necessary, and I can also take a video of it if necessary. The flickering is slow enough to notably see the line blink on and off at seemingly random intervals, the line being visible more often than not.

PM me for the image I guess because I can't post it, but it's on imageshack.


This line can be of any variety of given colors, but usually it flickers on and off the same color in a repetitive motion. No videocard setting through default NVIDIA controls or any tweak utility will actually get rid of the problem. Two noteworthy settings are, however, VSync and Antialiasing.

When enabling VSync, I am able to completely solve the problem in all 3DMark programs. Unfortunately, by the same token, enabling VSync makes the line flicker much more often in all the other games I have tested with, such as CS:S, Swat4, and Doom3. I also get a side impact of getting mouselag whenever I enable VSync, so I would prefer not to use it. This mouselag can not be fixed so long as VSync is enabled.

When enabling Antialiasing, I can seem to actually improve the problem dramatically, making the flickering occur less often. Unfortunately, it is not a given fix to the problem and in itself does not correct the problem, still occasionally visible. The thing I have noticed about this and VSync is that usually the flickering line occurs when I am approaching 60 frames per second. USUALLY and NOT ALWAYS, but this may have something to it, for enabling antialiasing makes me reach this threshold much less often, and thus the flickering much less often. Regardless of if this is meaningful, it is the result of my tests.

Changing the actual refresh rate of the monitor being operated has no impact, and neither does resolution. The funny thing about resolution is that when running any non-native resolution on an LCD, if you disable monitor scaling, the image will be presented in a centralized format at the middle of the screen. Much like watching a widescreen DVD on a fullscreen TV, there are "black bars" all around the display. So when the display is being done in the very center of the screen, not physically reaching the corners or edges whatsoever, I do not correct the problem. That's right, the flickering line still occurs, only not at the physical edge of the screen, but at the edge of the active display. This means that the flickering line takes place in places physically different from one another, indicating that, or at least I would assume, it is not faulty transistors creating this problem. Moreover on transistors, when I connect the LCD to the DVI output on my laptop, with an ATI card, I am unable to reproduce this graphical corruption whatsoever. There is no problem with the LCD at all when doing just this, meaning that, or at least I would assume, it is likely not the monitor at fault,

I have done all the software testing that I can see worth my while as being done. I have formatted multiple times and installed only bare minimum drivers to still produce the problem. I have run with probably 30 different drivers and had no impact aside from raw game performance. I have flashed my XFX 5900 videocard to different BIOSes, including 5950U, to no effect aside from other graphical corruptions until I underclock the card dramatically. I have installed different drivers, no drivers, different programs, and no programs, nothing to have impacted the problem whatsoever. It is not a software or driver thing as far as I can tell. I have even gone as far as installing Windows XP 64 Bit edition, alas to no avail.

I have tested in three different motherboards with three different videocards and not affected the problem at all. I have also wasted $50 and bought a new DVI cable to no effect. The only similarity I have noticed is that all 3 cards are NVIDIA and all 3 motherboards are ASUS, but is this even meaningful?

Now on to another interesting aspect: testing on my friend's P4 computer with his own LCD. I didn't have much time available to me, so rather than testing actual games on his computer, I just had time to test the different 3DMarks. When using any of the 3 NVIDIA cards on HIS system with HIS NEC LCD, I was still able to reproduce the flickering line. THIS IS NOT THE SAME LCD AS MY OWN NOR DOES IT CARRY ANY REAL RESEMBLANCE IN TECHNICAL ASPECTS, or at least as far as I can tell. That's right, 3DMark had the flickering line in the upper right hand corner, incidentally white in 03 and 05, red in 01, on his LCD on his motherboard with any of the 3 NVIDIA cards. This is starting to look like a massive, massive coincidence. Sure enough, no problem with the ATI card on the laptop connected to his LCD.

As of this point, I am not sure what else to do. Beyond just ignoring the problem, which is decidedly NOT an option, I am clueless as to what more to do next. Do I buy a new LCD? My friends has the same problem, and his is a different brand, different size, different refresh, different size, etc etc, the only similarity being 1280x1024. Do I buy a new videocard? 3 different NVIDIA cards by 3 different brands reproduce the same problem. Do I switch to an ATI card? I have not actually had the chance to test with an AGP ATI card as of yet, as I don't know anyone with one. I also would prefer to stay with NVIDIA, so long as possible, because NVIDIA has the Digital Vibrance feature that ATI has nothing to counter with, and this is a feature I love. It makes my desktop look so much better than without that there really is no comparison. It's not the cable, it's not the card, it's not the screen itself, what on earth can it possibly be?! I'm just speculating from this point on.

I tried taking my computer to a local tech shop, but obviously they don't "deal with monitors" and it's not directly a problem that can be traced to my physical computer, so far as I can tell.

What more can and should I do? Should I ditch NVIDIA and try obtaining an ATI AGP card to test with if not keep and go for a new ATI card without my ever-loved Digital Vibrance?

One thing I have noticed from my frequent internet searches is that a lot of people seem to have a problem I believe to be similar in nature to mine when using mostly widescreen LCD displays with SLI and NVIDIA cards. It was deemed to be a driver failure and a new driver set was released to correct the issue, but these drivers do not help me. The issue was basically described as a flickering line present only when using SLI, in some cases without widescreen but mostly with widescreen, at the top of the screen only present when using DVI and not analog. Is this problem the same as mine? Nobody every came forward with my model of LCD as being a problem, nor my friend's NEC, but a couple people did come forward with different standard 4:3 (well not actually 4:3 in the case of 1280x1024 in technical terms, but lets ignore that) LCDs and DVI vs Analog. It was really these complaints that made me wonder if my problem isn't an NVIDIA system-wide problem as it was claimed this problem was, but apparently, so far as I have been able to tell, new drivers have fixed these concerns. The very same drivers that reportedly correct the graphical corruption with SLI do not correct my issue. Furthermore, some people have reported that they have no problem when disabling SLI with any given resolution, this obviously not applying to me. I use no SLI and no widescreen. Is this issue even relevant? I don't know, maybe someone else does and can help..?

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