Should I switch to BNC?

[itim100]

Say you have a video card with D-Sub and DVI outs, but a monitor with both DSUB and BNC inputs, would it be better to use a DSUB->BNC converter/cable (or DVI->BNC) or to just use the DSUB?

[microfire]

I wanna know the answer to this question too.

I would guess that DVI to BNC would give the best image?

Anyone here know???

[HotKoala]

I biggest advantage BNC would give over DSub is the bandwidth. Otherwise any image quality difference(if any) you're really seeing is because manufacture cables have less than ideal quality.

If you use a resolution above 1280X1024, you should go BNC.

[Veland]

Also, the difference is larger when you are using longer cables. With BNC you can go for longer cables with high resolution without much ghosting.

But there IS a big problem: BNC cables doesn't carry any monitorID signal, so your card may default to standard VGA display! Sometimes this can be forced easily, but my ATI8500 gave me so much trouble that I switched back to dSub cable..

[itim100]

oh really? Well im definitely getting some kind of bnc adapter. I have a small monitor (17") , so a bit clearer 1920x1440 will be a real asset to me. But is that only good if I have a bnc output? If not, which adapter should i get, a DVI-BNC or Dsub-BNC? I would think D-Sub would be better...

HotKoala, (yer the dude who runs three LCDs off his parhelia, right?) I would notice the differenct alot if i was running 1920x1440?

[HotKoala]

I don't think I've ever seen DVI to BNC. That's mostly because I don't use analogue connections anymore so I don't pay mind.

Dsub to BNC is probably all you'll be able to find. It used to be that BNC was better quality than Dsub, but video cards with BNC out don't exist anymore. Now it is more for the video bandwidth.

I honestly think that at 1920X1440 on a 17" monitor, you won't be doing so well. One, it's a monitor's limitation in that, even though it can go that high, that is hardly the optimal resolution. That is probably your biggest bottleneck. After that would be your videocard, then finally, your cable.

[microfire]

DVI to BNC http://www.pccables.com/00679.htm

Though available, very expensive. I would think maybe this one is a good qualitly cable?
Not sure what is meant by Analogy DVI-A-M.
Maybe it says that since signal would need to be converted from digital back to analogy to work?

[HotKoala]

DVI-A-M = DVI-Analogue-Male connection

Since all signals are supposibly seperated from each other, that BNC cable would actually improve your image quality over DSUB-BNC.

Thanks for bringing those cable's existance to my attention=)

[donny_paycheck]

Remember that if you use an adapter the signal still starts out as DB15. Thus, DB15 is still the weakest link. You won't gain anything by increasing maximum theoretical bandwidth after the bottleneck.

[itim100]

yeah, that's what i thought, donny_paycheck.
screw it, ill just use dsub

hey, don't underestimate my iiyama, hotkoala, it is pretty sweet for $60. Looks great up to 1600x1200, and there are a lot of 19" monitors that can't do 1920x1440... :D

thanx for the info people. I will try switching my primary monitor on to the DVI-DSUB adapter (instead of my secondary monitor) and seeing if it looks any different than when it was on DSUB.

[donny_paycheck]

What type of video hardware outputs in RGB via BNC anyway? I've only seen it used in high end workstations with proprietary graphics adapters. AFAIK cards like FireGL and Quadro output only in DB15 and DVI like desktop cards do.

[HotKoala]

Old Number 9 cards did.

DVI-I/A doesn't start out like Dsub, hence the better quality.

[microfire]

Just got a DSUB - BNC cable today.
Tested it out on on both video card heads, DSUB and also on the DVI with DSUB adaptor.
I found that there is no difference with my particular monitor, no matter if I used the standard DSUB cable or the BNC cable.
The turth is theres no point getting a BNC cable. There no noticeable change in image quality and you lose DDC.
I tryed higher res 1600x1200 and also 1920x1440, both these resolutions I did not notice any better quality. Its been said that when the benifits of BNC come into play at over 1280x1024.

The moral of the story: I just ripped myself off $26 today :(

[HotKoala]

I'm hoping you didn't buy one of those generic or Belkin brand cables..

In addition, your monitor was probably blurry at a lower resolution. A less than adaquete monitor will not be fixed by a mere cable, no matter how good it is made.

[microfire]

The brand name was SI. I never heard of it and the price was cheap, it more than likely generic since they send me the cable and nothing else. The cable works out to be about $16us dollars.

Your right with my monitor, only a 19" trinitron tube. Its very soft around the egdes, that where the convergence begins the become bad. Not much I can do about, I got a service person out to check but he insisted it was within spec.

[HotKoala]

I don't doubt the resolution was in spec.

I'm saying that monitors that list their highest max resolution and refresh rate to attract buyers when in reality their optimal image quality resolution is indeed much lower. It's a great marketing scheme that works.

A generic or Belkin brand cable isn't much better off than an OEM cable. At the very least, you have a quick replacement if you cut a cable of if the OEM supplied one if too short, it can be replaced.

[microfire]

Gone back to using oringal DSUB cable.
Optimal resolution in the owners manual for my monitor is 1280x1024 @ 85hz. I find this setting is not that hot. Slight fuzzy/blur to it, almost as if 19" size is not big enough to cope, also my dot pitch is only .24. This res is usable.
Anything above this res seems to have much the same fuzz/blur, displays ok considering the detail is becoming finer. 1940x1440 is even usable, all text can be read, but the 60hz refresh rate flicker at this level is enough to drive you mad in only mintues.
Best resolution that works for me is 1024x786 @ 85hz. There is still a slight blur to some black text on white backgrounds, mostly on the right hand side of the screen.
So that means yes HotKoala you are right. The monitor is less than adaquete, well only in my eyes, it still acceptable to +95% of peoples.
Have said all that and the adventure. I have come to terms with what I have now, I have realised that this is how it is. This page here helped with my addiction of conquest for the best. Put things into perspective. I see that there is no perfection. I really have to much time on my hands. Its been good to learn though.
http://www.repairfaq.org/sam/monfaq.htm#