DVI-I/DVI-A cables for CRT monitors?

kennyj

Junior Member
Jan 11, 2004
13
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I just got my hands on a pair of IBM C220p monitors. I also happened to have a nice GeForce 6800GT dual DVI video card on hand. The monitors each came with a DVI-I->VGA cable, and each have a DVI-I (analog) and a VGA port. I'm under the impression that analog DVI-I is to be a replacement of sorts for VGA->BNC on higher-end monitors, but I digress.

Currently the cables (which seem to be okay, but they *are* stock cables) are connected to the VGA inputs on the monitors so the DVI ends are attached to the video card.

Everything is peachy until I hit 1600X1200, where I start to see what can only be described as a slight "glow" or "fuzziness" towards the edges of the screen when viewing text. Most people probably would never notice, but... yanno. Spend 10+ years staring at CRT and LCD screens and you start picking up on crap like this.

As this is nowhere near the monitor's max resolution and the video card seems to be pretty decent, I'm placing blame on the stock cables, or at least on EMI they could be picking up on and not sheilding against properly. I've not managed to find too many "true" DVI-I cables that don't suck (Cables with DVI-I connectors are standard but almost always have either digital-only wiring (missing the four prongs around the wide flat connector at one end) or have a VGA connector at the other end.) In fact, these are the only ones I've found so far:

http://www.cablestogo.com/prod...Fid=2030&sku=26948
http://www.computers4sure.com/...its=4&HKeyword=dvi
http://www.markertek.com/Produ...&search=0&off= (not sure if this one is an I or a D-only)
http://www.markertek.com/Produ...&search=0&off=
The single and dual links here:
http://www.ramelectronics.net/...itor_cables.html#DVI-I

Based on what little information is actually given with these, I'm inclined to believe that the one at cablestogo.com is best simply because they include some specs and they point out that the analog lines are coaxial with individual braided copper shields. I'm under the impression that this is likely better than stock DVI->VGA cabling like what I'm using. computers4sure.com's cable has the distinction of being the only actual DVI-A cable I can find, though it needs not be said that this makes no guarantee of the its competence. The rest, I'm flying blind unless someone here has experience with the manufacturer.

Any thoughts on the merits of going DVI-DVI over DVI-VGA, and on my selection of cabling so far?
 

kennyj

Junior Member
Jan 11, 2004
13
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0
I've asked a friend and gotten a recommendation for cablestogo.com, really for anything they carry. After doing some more poking on the site I found information about the construnction of their cables, something lacking everywhere else I looked besides bluejeanscable.com (or, rather, AV Link, their cable supplier) and even then in far greater detail. What little I've found suggests that their cables are top-quality if the specs mean anything (both braid and foil shielding, full shielding in the connectors, end-to-end grounding, etc.) and the fact that they actually talk about it might be telling in and of itself.

Anyone have any more info, possibly?
 

yhelothar

Lifer
Dec 11, 2002
18,409
39
91
I had the P275 monitor, and it came with a DVI-I to VGA cable. I didn't see any image quality improvements using VGA-VGA to DVI-VGA, to DVI-DVI
 

imported_halcyon

Junior Member
Aug 30, 2004
17
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The signal in D-Sub (15-pin aka so called 'VGA' misnomer) DVI-I (the analog part) and 5xBNC component is exactly the same (analog RGBHV signal).

The connectors best suited for this job is BNC, because it gives you the closest to the nominal termination impedance (75 Ohm) for reducing reflections in the cable.

That is, properly constructed, BNC connectors offer better signal quality at high signaling rates than either D-SUB ('vga') or DVI-A (part of DVI-I).

As for the cables, I suggest you look at www.bettercables.com .

They do cost a premium, but they detail how they build them, they have a money back guarantee and lots of happy high definition video (which requires a lot of badwidth as well) customers.

 

kennyj

Junior Member
Jan 11, 2004
13
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halcyon: I actually wanted to get one from there, but they don't seem to have any DVI-I or DVI-A cables. DVI-D, no matter the quality, just doesn't work here. Had these monitors supported it, I'd probably be on BNC already (I have one cable, and unlike DVI-I you can actually pick them up locally.)

virtualgames0: Under what circumstances were you comparing the different cables?