Are all DVI sources from video cards really the same?

[xMax]

Here is a quote from DisplayMate with regards to image quality and DVI Video Cards:

Quote:
In principle all DVI sources are equivalent. In practice some combinations of graphics
boards and monitors don't work properly together.

Naturally, with my luck, i am one of those individuals who has experienced an incompatbility between a monitor(CG210) and a video card(ATI X1800XT). The artifacts produced from a DVI connection between the two was essetially screen speckles. And this was validated by a technical note that i found on the Eizo web site that clearly stipulated the incompatibility.

So after seeing that note, i went out and returned the ATI card in exchange for a BFG Geforce 7800GTX. And sure enough, the Geforce 7800GTX actually cleaned up all the speckles. But not entirely, for there are some remnant speckles that remain, which could be caused from the GTX or from damage to the CG210 from having been connected to the ATI card. So out of complete frustration and paranoia, along with the disliking of these horizontal electrical surges that appear on the CG210 when the computer boots, i decided to let go of the Geforce 7800GTX.

So i went out and got a BFG 6600GT OC in order to see if the bootup screen surges would go away. And to my luck, they did. The computer now boots nice and cleanly without any screen blips or surges of any sort. Of course, the tiny remnant speckles still remain, as this has gotten me to question wether there really is no such thing as image quality when it comes to DVI.

What do you guys think? Would a midrange desktop card like the 6600GT really have the exact same DVI signal quality as an ultra high end Quadro FX 4500? Or could it actually be possible that a professional workstation card like a quadro would actually have better signal quality which would in turn result in a better image displayed on the same screen that would have been connected with a desktop card like the geforce 6600GT?

I mean, technically, digital is digital, and should not have in betweens like analog. it should be 100% or 0%. But after what i saw with the ATI card, i started thinking that maybe the card i have has some kind of an incompabitility at a very minute scale that would be causing these remaining speckles, and that getting a high end professional card would have a higher quality that would in turn result in a high likelyhood of less potential incompatibilities.

Its so confusing. Maybe im just paranoid. After all, Eizo didn't mention any incompatibilities between their Monitors and Nvidia cards.

P.S. According to my computer buddy, those electrical surges would not have damaged my monitor. They are apparently just horizontal scan lines of some sort that the graphics card does to adjust itself with the monitor. Or something like that. I cant fully recall what exactly he had said except that there would have been no damage to the monitor. My point is that the remaining speckles that i see would not have been caused by the blips that the 7800GTX was producing with my monitor.

 

[Matthias99]

Have you considered that the problem might be the monitor? You're now on your third video card, and the odds that all of them are having strange graphical anomolies is slim. Also, the note on their website lists how to work around the ATI issue (by checking an option in the drivers for 'alternate DVI operational mode').

Digital signals are pretty much going to get there or not, but it is possible to have signal integrity issues when you are pushing the limits of a transmission spec. However, any ATI card should do 1600x1200@60Hz over DVI without a problem. NVIDIA cards may need to use reduced blanking intervals, since their DVI implementation has been shown to be somewhat spotty, but it still usually works fine.

 

[dorkbert]

I had no end of problems with 6600GT and SGI 1600SW/Multilink (DVI). All the problem disappears if I swap the 6600GT with an ATi card or older nVidia (GF3 vintage) card.

 

[xMax]

Matthias99, i have considered that the problem might be the monitor. But before i reach that final conclusion and RMAing the monitor, i have to be absolutely sure.

Now you said that the odds of all of them having strange anomolies is slim. This is true, but the anomoly with the ATI card was absurd. There was an insane amount of speckles. With the two geforce cards i tried, the speckles were just about completely removed. So they are not the same type of problem. The ATI cards have a design incompatibility, whilte the geforce cards seem to have a deficiency.

And i tried checking the alternate DVI operational mode, but it didn't change a thing. I tried changing signals on the monitor and outputs on the card, but again nothing changed. If you read carefully at the technical note by Eizo, they say

There is no measure to fully eliminate these problems because they occur due to a PC- monitor compatibility fault. Try the following to improve your display quality".

Which basically says you cant actually fix the problem, but you can try to do something to slightly improve the quality of the display. But i say no thanks! If you read behind the lines, you can see that there is actually no fix to this problem. I spent 3000$ on a monitor that should be displaying images to its greatest capacity, i will not accept an incompatible video card. But this is besides the point, because nothing changed and the speckles were horrible.

However, with all said, I must say that what you mentioned about nvidia cards having problems with signal integrity, which i know has something to do with Nvidias internal TMDS transmitters, is definitely of interest to me.

Here's another quote i just found from DisplayMate:

One issue that occasionally affects DVI (but not HDMI) is the use of components that are not fully compliant with the official DVI specification. This problem arises because official compliance testing is not required for DVI components (but it is for HDMI). When there is a compliance problem some DVI signal sources (like computer graphics boards or DVD players) may not work properly with some DVI receivers like displays. This generally leads to image artifacts like on-screen noise. The problem is more likely to appear at higher resolutions and longer transmission distances. Historically only a small number of combinations have resulted in a problem and it?s less common now.

Notice the artifacts that are likely to occur, 'screen noise'. My goodness, thats exactly what im seeing.

But again, the ATI card was different. It was a very unusual kind of noise that clearly was caused by a circuit design type incompatibility. But the noise im seeing witht he Nvidia cards cannot possibly be a design incompatibility since Eizo would have mentioned it. For this reason, it could only be the result of a weak TMDS transmission.

Here is another interesting quote from an article written by extremetech on DVI compliance. After showing how so many of Nvidias desktop cards have weak DVI signals, the author writes this about Nvidias professional workstation cards after showing how it passed the DVI compliance test:

Result: Both Quadro FX 2000 ports pass at 162MHz.

nVidia's taken no chances with its professional line of graphics boards. The Quadro FX 2000 is based on the company's GeForceFX 5800 architecture, but uses two Silicon Image Sil 178 transmitters, which allow the card to drive dual-DVI, very high resolution displays, as well as two separate monitors. The board is robustly constructed and the signal paths generate a clean, unambiguous DVI signal. At the prices these boards command, it's comforting to know that both DVI ports can drive 1600x1200 displays without any issues.

So i guess a workstation card will guarantee a flawless DVI signal transmission with respect to the TMDS transmitter issues on video cards, ATI and Nvidia, since ATI also has had issues, but clearly not as much as Nvidia.

What do you think Mattias99?

 

[Matthias99]

Originally posted by: xMax
What do you think Mattias99?

Based on your previous posts, I think that you come up with the absolute weirdest problems I have ever seen, have absoutely incoherent "logic", and will not listen to any advice you are given anyway.

I have no idea what kind of "design incompatibility" ATI might have wrt this monitor; ATI appears to have followed the DVI spec to the letter (unlike NVIDIA) with their cards, and they work just fine with every other LCD monitor on the planet.

My guess would be that you have a defective monitor, since it is not working with NVIDIA cards either. But go buy a Quadro if it makes you feel better.

 

[xMax]

What the hell are you talking man. I have eyes, and i know what i saw. Those speckles were completely visible. And by lowering the resolution, they became 100% clearly visible to the point where it was totally unnacceptable. I mean there was all kinds of speckles or bloches on my screen.

And if you read Eizostechnical note carefully, they clearly stipulate that there is NO MEASURE to fully eliminate these problems because they occur due to a PC- monitor compatibility fault.

What part of that statement declaring the incompatibility did you not believe.

And after getting rid of the ATI card and getting the Nvidia Geforce 7800GTX, about 95% of the speckles were completely gone. And i then reduced the resolution to see if they would be more visible, but there was virtually no speckles what so ever.

This CLEARLY means that the ATI card was incompatible. And i followed their instructions to try to fix it by checking the alternate DVI operations and downloading the latest drivers, but nothing changed.

Anyhow, i can see your point. I know you have followed many of my posts. I remember your name. And i have the most bizzare issues and often dont listen to anybody. But i dont think that my concerns right now are weird. Nor do i think that my reasoning is incorret.

You are wrong in this matter Matthias. Your opinions and advice are no longer wanted.

I think im certain that i have identified the problem. I just have to find out if my current Geforce card meets all the DVI compliance specs. And if it does, then the problem will clearly be my monitor.

But i guess i dont need advice from anybody anymore.

 

[Avalon]

Since you don't need advice anymore, I'll feel free to comment.

Which basically says you cant actually fix the problem, but you can try to do something to slightly improve the quality of the display. But i say no thanks! If you read behind the lines, you can see that there is actually no fix to this problem. I spent 3000$ on a monitor

Almost makes it sound like Eizo built a defective monitor and slapped a disclaimer on it, the way you word it. Anyway, $3000 for a 21.3" monitor with subpar specs?

 

[xMax]

That cant be. The CG210 is not a defective monitor. Its actually the best monitor on the planet when it comes to image quality. This is based on Toms Hardware Reviews, DisplayMates awards, opinions by professional photographers in a forum where they are always talking about the highest image quality monitors up to date, and its based on specifications. Not to mention that all companies selling monitors to imaging professionals, who only buy the highest image quality displays, always recommending the CG210.

More than that, the ATI cards are also incompatible with a whole bunch of other Eizo monitors. And Eizo is actually THE world leader in high end LCD displays.

But wether i have a defective monitor, or wether i somehow have damaged it by screwing around with it the way i have been, that is certainly possible. And what i must first do is make sure that my computer is perfect before proceeding to RMA the monitor, which is precisely what im trying to do.

The only thing is that while a quadro will guarantee top quality, the BFG Geforce 6600GT OC may still have perfect DVI signal quality, as this would mean that i would not have to waist money on a quadro. But how can i know this? That is the present issue that i must resolve.