DVI Cable question

Posted by: Darth Tater

DVI Cable question - 11/14/06 06:26 PM

I have some DVI cable questions!

First off, let me say I'm not much up on DVI cables so if I say the wrong thing please forgive me. Here's the deal:

When I installed my projector I went ahead and ran a DVI cable. However I used whichever DVI cable the 990's connector does NOT have...I have the DVI with all the pins and the 4 little extra pins (I think my cable is DVI and Analog) and of course the Outlaw does not have the 4 extra pins and my cable does not plug into it.

I guess the question is...do I need these 4 pins for anything? Can I just break them off so I can use the DVI cable with the 990? I hesitate to break them in case they need to be there in the future for something. If I were to plug a laptop with DVI output into it would I then need the 4 pins?

Here's what I'm trying to do in case you're curious...now that the Xbox 360 has the killer HD-DVD drive I'm wanting to get the VGA adapter for it and plug it into the DVI input using a VGA-DVI adapter...is there any reason why this shouldn't work? Thanks!
Posted by: gonk

Re: DVI Cable question - 11/14/06 08:11 PM

Those four pins above and below the blade are associated solely with the analog side of DVI - something that your projector probably can't accept anyway and that consumer electronics sources don't normally support anyway (I've heard of exactly one DVD player that did).

If you use a VGA-DVI adapter, however, you are using the analog section of DVI. You need to confirm that your projector will even accept an analog DVI signal. If it will, keep those four pins. If it won't, ditch the pins and don't waste money on VGA-DVI adapters that it won't work with.
Posted by: Darth Tater

Re: DVI Cable question - 11/14/06 10:52 PM

Thanks Gonk.

My projector is an Optoma H31, I'll see if I can find the info about it. I know that the DVI plug on the projector does have the 4 pins on it.

And just let me make sure I'm hearing you right..even if I get the DVI cable to plug into the 990 via a convertor or by removing those 4 pins, using a VGA adapter wouldn't work anyway? So in this case I'd just have to bypass the 990 and run straight to the DVI cable?
Posted by: gonk

Re: DVI Cable question - 11/15/06 12:06 AM

Using a VGA adapter will work only if the display supports DVI-I input. DVI was developed as an interface for LCD computer monitors (which are digital display devices) and as such was a digital interface, but the developers were unwilling to abandon trusty analog video and allowed for three forms of DVI: DVI-D (digital only, single link or double link), DVI-A (analog only, for the familiar old analog video signals), and DVI-I (a connector that carries both digital and analog, so the device can input - or output, if it's a video card - either analog or digital based on your need).

Most of today's HDTV's either have HDMI (which borrows DVI's digital video side but left the analog video behind) or DVI-D. There are a few devices around that offer DVI-I (mostly front projectors, since many trace their lineage back to the business projector market). Only a DVI-I device will be able to work with DVI-VGA adapters, and then only if those four pins are in place throughout the entire signal path. According to Projector Central , the Optima H31's DVI input is a DVI-I input, so it would work with a VGA adapter, but if you can't plug a DVI-I cable into the 990's DVI ports without removing those four pins then you wouldn't be able to use the 990's switching with a VGA adapter in there somewhere.

Only loosely related question... When is Microsoft going to go ahead and find a way to put HDMI into the 360? For that matter (and get even more loosely related), I wonder if an inexpensive component to VGA adapter and a VGA to DVI adapter would be used to let you use that DVI-I cable to your Optima with all of your analog sources? (Component monitor output from 990 to the converter, converter VGA output to the VGA/DVI adapter, DVI-I cable from there to the projector...) It's late and my mind is wandering in potentially crazy directions.
Posted by: Darth Tater

Re: DVI Cable question - 11/15/06 03:45 PM

Hey, sometimes good things happen when the mind wanders to uncharted territory smile

I never really considered the VGA-Component adapter only because I figured it wouldn't really give any advantage over just straight component. I'd like to try the VGA to see if it gives any advantage over component but it's looking like it's going to go through about 16 adapters in order to do that. Maybe I'll just stick with component smile What got this all started was the HD-DVD drive for the 360, and the HD movies and TV show downloads coming for the 360. That will be nice.

I don't know why Microsoft didn't include HDMI, same reason Outlaw didn't maybe. I don't know. But it's no concern to me at this point, nothing I own has HDMI smile
Posted by: gonk

Re: DVI Cable question - 11/15/06 04:30 PM

If you don't have any sources that have digital video (and based on your sig, you don't have any), you are probably best off staying with component. The only reason you might want to mess with the component-to-VGA-to-DVI would be if you only had (or wanted to only have) a DVI-I cable running to your projector. Since you clearly already have component cable run, it would just be an exercise in adapter chaining.
Posted by: gonk

Re: DVI Cable question - 11/15/06 04:43 PM

And for what it's worth, since the 360's HD-DVD drive is limited to component video output anyway, the best output you will be able to get would still be 1080i since the VGA and component outputs are using the same AV connection. I'm guessing that the highest output resolution offered is 1080i, which component can do just as well as VGA.
Posted by: Darth Tater

Re: DVI Cable question - 11/15/06 07:36 PM

Actually the 360 outputs 1080p through the component, and I'm pretty sure through VGA also. It looks fantastic!
Posted by: Darth Tater

Re: DVI Cable question - 11/15/06 07:38 PM

Yeah, VGA also does 1080p.

http://gear.ign.com/articles/746/746074p1.html
Posted by: Machine

Re: DVI Cable question - 11/15/06 07:57 PM

You may want to check on this but as far as I know the 360 will output max 1080i over component for Movies and 1080p over VGA. Has somethign to do with the DRM bullshit limiting the output resolution over component connections. The downrez mandate does not apply to VGA connections however.

Tons of talk of this on AVS so you may want to double check there.
Posted by: Darth Tater

Re: DVI Cable question - 11/15/06 08:32 PM

Yep...

"While the Xbox 360 is apparently capable of outputting a digital signal, as Microsoft representatives informed us a few months ago (full article here) the current lack of HDMI limits the 360 to outputting 1080p signals via Component video or VGA. "
Posted by: gonk

Re: DVI Cable question - 11/15/06 11:14 PM

So they are actually pushing 1080p through component/VGA outputs? That should be a nice fit with VGA for displays, but what displays support 1080p input via component? I must have missed something among the newer 1080p TV's - didn't realize they were accepting 1080p analog.
Posted by: Darth Tater

Re: DVI Cable question - 11/17/06 09:25 AM

The 1080p works great with my neighbor's Samsung DLP, but not his Mitsubishi..which is older.
Posted by: Nalod

Re: DVI Cable question - 11/17/06 09:40 AM

Gonk,

If you may, Perhaps you can answer this question:

My Loewe Aconda 38 inche tube has component and VGA inputs. No HDMI or DVI.

There are some $499 converters that can go DVI to VGA which would be nice for connecting the 990 as you might well imagine.

$499 is steep to pay for this, but what I can't find out is will I really gain anything substantial. I have been told my upscaler in the Loewe is exeptional and feeding it component signals is just fine.

Picture wise, and this is all that matters, my old DVD player looks really nice as is. Same from my HD cable box into component.

But, If I can get some improvement and added convienence, why not?

Thanks!
Posted by: gonk

Re: DVI Cable question - 11/17/06 09:54 AM

Going from DVI to VGA means a digital-to-analog conversion, and at that point you are trusting the converter to have better video DAC's than whatever DVI-equipped source you were using. Granted, HD cable boxes aren't necessarily going to have the world's best video DAC's, but I'd be hard pressed to convince myself in this case that $500 would benefit me. The one case where I might find a DVI-to-VGA device compelling is HD-DVD or Blu-ray if studios had started using the ICT to limit resolution of component video outputs. Since that hasn't happened, I'd tend to stick with analog video in your case.
Posted by: Nalod

Re: DVI Cable question - 11/18/06 12:21 AM

Quote:
Originally posted by gonk:
Going from DVI to VGA means a digital-to-analog conversion, and at that point you are trusting the converter to have better video DAC's than whatever DVI-equipped source you were using. Granted, HD cable boxes aren't necessarily going to have the world's best video DAC's, but I'd be hard pressed to convince myself in this case that $500 would benefit me. The one case where I might find a DVI-to-VGA device compelling is HD-DVD or Blu-ray if studios had started using the ICT to limit resolution of component video outputs. Since that hasn't happened, I'd tend to stick with analog video in your case.
Thanks for the response. The clarity response is appreciated!