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Any difference between using DVI vs. SVGA cables with regard to display speed?

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Any difference between using DVI vs. SVGA cables with regard to display speed?

Old 11-17-04, 04:24 PM
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Any difference between using DVI vs. SVGA cables with regard to display speed?

Not sure if that title makes much sense, but...

A friend of mine (who's often FoS) told me that since I'm using a DVI cable from my video card to my monitor, that I might be getting a better picure, but I'm sacrificing display speed (a.k.a. standard cables are capable of faster throughput).
Is there any truth to this?
Old 11-17-04, 04:38 PM
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DVI is digital and I would guess it's faster than VGA (analog) as there is no conversion. It's a straight digital connection from video card to monitor.

If there is a display speed discrepancy it would be very minute. Even then, what application would cause this to be a concern?
Old 11-17-04, 04:53 PM
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Originally posted by BigDave
DVI is digital and I would guess it's faster than VGA (analog) as there is no conversion. It's a straight digital connection from video card to monitor.

If there is a display speed discrepancy it would be very minute. Even then, what application would cause this to be a concern?
Half-Life 2.
Old 11-17-04, 05:08 PM
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He's probably talking about the refresh rate. DVI is typically used with digital displays that work at certain fixed frequencies like 60Hz. With RGB displays, you can drive monitors at rates upwards of 100Hz+.

Most 3D games will, by default, cap their rendering speed at the refresh rate (e.g. 60 fps on a 60Hz DVI connection). So theoretically, with an RGB display, you can get games that display higher frame rates.

Personally, I can't see a difference between 60fps and 100fps, so I got no problem with using DVI.
Old 11-17-04, 07:45 PM
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Originally posted by belboz


Most 3D games will, by default, cap their rendering speed at the refresh rate (e.g. 60 fps on a 60Hz DVI connection). So theoretically, with an RGB display, you can get games that display higher frame rates.
I forgot to mention that my display is a LCD.
Not sure if that makes a difference or not.?.?
Old 11-18-04, 01:50 AM
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Doesn't matter whether it's an LCD or not, really.

Anyway, DVI can do higher refresh rates than 60Hz, in theory. Problem is that few video cards can actually do that. Most limit the refresh to 60Hz. The thinking kinda goes that if you're using DVI, you're likely using a digital display like an LCD or plasma or something. These types of displays don't suffer from the flicker problem that CRT and other analog display methods do.

60FPS is about the maximum the human eye can see. Anything above that is gravy, more or less. However, a CRT refreshing at 60Hz causes eyestrain over time, because it tends to flicker in a way that you can see. So for these, it's best to use something higher.

But a CRT is analog in the first place. You have an electron beam pointed at you which is firing electrons at the phosphors, making them glow. It scans the whole screen, left to right, top to bottom, then repeats. An analog signal controls the firing of the beam.

A digital display, like an LCD, doesn't work on the same principle. Every little pixel in the thing is individually controllable. To make it work with old analog connections, it has a little converter in there to emulate that screen refresh methodology. But the LCD is an active thing. Those pixels are emitting light themselves, not being hit by an electron beam. They don't flicker. You turn them on, you turn them off. So 60Hz is perfectly fine, because they're not turning on then dying off when some beam moves elsewhere. DVI is controlling those pixels more or less directly, by feeding the screen content to the display in a digital manner.

In other words, yes, you're limited to 60 FPS most likely. But BFD, you can't actually SEE more than that in the first place. The only reason higher refresh rates were good was to avoid flicker in analog displays. The fact that you could get a higher framerate out of this was just a side effect. Games tend to limit the FPS to the refresh rate in order to avoid "tearing", which is a whole other subject.

Anyway, because they're not concerned with preventing flicker, digital video methods like DVI operate at 60 or 72 Hz, usually. 72 Hz is sometimes used to avoid having to deal with the problems when you reverse 3:2 pulldown.

Last edited by Otto; 11-18-04 at 01:53 AM.
Old 11-18-04, 11:09 AM
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The biggest problem with playing games on an LCD is purely the response speed of the LCD panel.

A good LCD will have a 16ms response time which means anything over 62fps (1/.016) will smear or ghost. The liquid crystal pixels simply can't turn on and off any faster.

There are some newer LCDs with a 12ms response time which would allow up to 83fps and would be more suitable for games. However CRT is really the best display for fast-action games.

DVI is absolutely the interface you want to be using for a 17" or larger LCD.

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