DVI to VGA adaptor, any disadvantages ?

johny_rotten · Sep 14, 2007, 08:34 AM

I'm thinking about buying the Sapphire Radeon X1950Pro AGP, Newegg.com - SAPPHIRE 100171L Radeon X1950PRO 512MB 256-bit GDDR3 AGP 4X/8X HDCP Ready Video Card - Retail

It has dual DVI out and I don't know much about what DVI is accept that's I think it's made for LCD displays. I still have my beloved Sony Trinitron CRT monitor.
I'm just wondering if there are any disadvantages to using a CRT on the DVI out with the adaptor? I never run resolutions above 1280x1024

If anyone out there is using a CRT on the DVI out I'd like to know what they think.

Thanks,
Johny

Judas · Sep 14, 2007, 08:36 AM

Disatvantages..

hmmm, if i recall right, generally NO.... however, with analog going the way of previous now dead animals....... it's starting to get a little on the not really thought of much anymore side.

You shouldn't have a single issue using the already Bundled DVI-VGA adapter that'll come with it all. Plug er in, and you should have a nice crisp clear perfect image.

Just Learnin' · Sep 14, 2007, 09:17 AM

Works fine on my Sony G520. The only thing that looks weird is the ASUS logo on the mobo boot screen before it carries on to boot into windows.

Dyre Straits · Sep 14, 2007, 09:46 AM

Quote:

Originally Posted by Just Learnin'

Works fine on my Sony G520. The only thing that looks weird is the ASUS logo on the mobo boot screen before it carries on to boot into windows.

I turn off the motherboard Logo on all my systems.

swimtech · Sep 15, 2007, 04:00 AM

You know, this is a great question that I don't remember ever really being asked... The answers you've gotten are good, and correct, but why? This surprised me a couple years ago...

DVI is of course, Digital Video Interface, and is ideally suited for controlling digital technology based displays like LCDs and so forth. The high bandwidth, along with not having to convert the video data stream to an analog signal makes for the cleanest possible movement and display of the data.

The light beamed from behind the digitally positioned LCDs to create color convert that digital stream from the video card to a frequency of light that your eyes can send to your brain. Voila, Sam gets Serious - with you!

The surprise for me was finding out that the DVI-I connector has those four holes on the right - over and under the line shaped connector hole - that carry good ol' analog RGB, or VGA in other words. They um, hedged, no helped - yeah, that's the ticket! We still need VGA on there somehow so we'll give 'em four or five pins on our new connector (that's all that was ever really needed anyhow...) for VGA/Analog displays until they fade out.

No, really though, it's difficult technically to transmit a high res analog VGA signal (1600x1200 or so, and up...) across wires of any kind or distance. Color information changes phase slightly, luminance loses its reference and changes amplitude, and more. And the circuitry needed to process that signal is expensive and inaccurate compared to processing/transmitting square waves with control bits in a digital video data stream. Quality and cost - that's why video is going digital, and has been for years. It's easier electronically to originate, process, and transmit at high resolution, and cheaper to manufacture - but I digress, sorry...

The DVI-I connector's four holes can be routed through the adaptor to the VGA pins of your older monitor's cable without conversion or noticeable distortion at all - it's just a jumper to match the VGA cable. There's no active conversion or changing of the signal coming from the video card at all - and at the resolution at which you run your Good Ol' Sony (of your Owney - remember that commercial - no?) it will be just like coming off a standard VGA connector.

H3X4D3C1M4L · Sep 15, 2007, 05:51 AM

Quote:

Originally Posted by swimtech

You know, this is a great question that I don't remember ever really being asked... The answers you've gotten are good, and correct, but why? This surprised me a couple years ago...

DVI is of course, Digital Video Interface, and is ideally suited for controlling digital technology based displays like LCDs and so forth. The high bandwidth, along with not having to convert the video data stream to an analog signal makes for the cleanest possible movement and display of the data.

The light beamed from behind the digitally positioned LCDs to create color convert that digital stream from the video card to a frequency of light that your eyes can send to your brain. Voila, Sam gets Serious - with you!

The surprise for me was finding out that the DVI-I connector has those four holes on the right - over and under the line shaped connector hole - that carry good ol' analog RGB, or VGA in other words. They um, hedged, no helped - yeah, that's the ticket! We still need VGA on there somehow so we'll give 'em four or five pins on our new connector (that's all that was ever really needed anyhow...) for VGA/Analog displays until they fade out.

No, really though, it's difficult technically to transmit a high res analog VGA signal (1600x1200 or so, and up...) across wires of any kind or distance. Color information changes phase slightly, luminance loses its reference and changes amplitude, and more. And the circuitry needed to process that signal is expensive and inaccurate compared to processing/transmitting square waves with control bits in a digital video data stream. Quality and cost - that's why video is going digital, and has been for years. It's easier electronically to originate, process, and transmit at high resolution, and cheaper to manufacture - but I digress, sorry...

The DVI-I connector's four holes can be routed through the adaptor to the VGA pins of your older monitor's cable without conversion or noticeable distortion at all - it's just a jumper to match the VGA cable. There's no active conversion or changing of the signal coming from the video card at all - and at the resolution at which you run your Good Ol' Sony (of your Owney - remember that commercial - no?) it will be just like coming off a standard VGA connector.

Well put to say the least.

I would doubt highly you'll notice any form of degredation all the same... especially if you're running >= 1280x1024

johny_rotten · Sep 15, 2007, 06:14 AM

Thanks for the replies, and thanks Swimtech for clear and to the point explanation of how DVI works an why it makes sense.

I'm ordering the Sapphire Radeon X1950Pro AGP right now.

Johny

aNy_oNE · Sep 15, 2007, 07:54 AM

Yeah, thank you for that :P I will be upgrading soon but keeping this CRT monitor, so that's nice to know.

Judas · Sep 15, 2007, 08:17 AM

But the Newer video cards use a DVI-D connection..... which although have the analog pins... but i've seen some motherboards with both a VGA and DVI port, however, the DVI port only has the thin pin, without the other pins surrounding it.. making it impossible to use a DVI-VGA adapter.

Fig · Sep 16, 2007, 04:54 AM

Any time you convert a signal from digital (DVI) to analog (RGB) or vice versa you are going to get some signal loss. That said as the others have said you probably won't notice it.
My system is very close to yours and I'm getting very poor performance. Let me know how you make out with the new card.
Fig

H3X4D3C1M4L · Sep 30, 2007, 05:31 AM

Quote:

Originally Posted by Judas

But the Newer video cards use a DVI-D connection..... which although have the analog pins... but i've seen some motherboards with both a VGA and DVI port, however, the DVI port only has the thin pin, without the other pins surrounding it.. making it impossible to use a DVI-VGA adapter.

I think you typoed.... new cards all come with a DVI-I port (and now some cards have HDMI compatible DVI ports). You are correct though... an adapter for DVI-I to DB15 won't work on a DVI-I port.

Judas · Oct 2, 2007, 07:21 PM

DVI-I are a single DVI connection.... correct?

where as DVI-D which i beleive all new cards use now, have a dual dvi connection.. (this allows for higher resolutions such as a 30" 2560x1600 or higher... DVI I supports 1920x1200 as the maximum value correct?

from what can tell from the pining on the dvi ports.... any DVI port supporting a VGA adapter... basically already DOES VGA mode, techically it's not taking the dvi digital signal and changing it over to a vga signal.. it's already VGA coming out of the 4 pins? that are on the dvi port and mapping them to fit the 15pin vga port correctly.... ..

swimtech will likely know for sure how that works though.

I'm more interested in the DP connections now.

swimtech · Oct 2, 2007, 09:41 PM

Hey all,

I found this

that explains what matters when dealing with the differing DVI type connectors rather simply.

A DVI-D connector cannot be adapted for an analog VGA cable without active conversion circuitry because the analog signal does not exist via that connector.

The single link DVI cable is missing 6 pins in the center. The dual link DVI connector has pins all the way across. You can have single link or dual link cables in either DVI-I or DVI-D varieties.

The video digital to analog conversion is done on the video card, then routed to the four pins on the DVI-I connector (or to a VGA connector). D/A conversion of digital computer video has been being done for a very long time (ever noticed the RAMDAC specs for video cards all these past years - that's the frequency of the video digital to analog converters - the higher the better) and is quite mature. The same type of conversion is done in DVD players for output via composite, component, or S-video outputs.

So, it should be apparent that eliminating the RAMDACS on the video card and providing only digital output to a monitor via a DVI-D connector should be cheaper for the manufacturer. It decreases flexibility for us users, but should (theoretically...) provide the highest quality output because there are no conversion losses or artifacts - tiny though they are...

High res VGA looked pretty good for the past decade or so didn't it?

From the more than you probably wanted to know department - think about this...

Basically, the D/A conversion still happens, but only once. The conversion has moved out of the video card, down the cable, into and through the monitor, all the way to the display panel itself. The LCDs themselves serve to convert the digital video data to analog light waveforms (with the assistance of the backlight in an LCD display) for perception by your eyes. A ton of circuitry and processing have been eliminated by keeping the video digital all the way to the panel.

Pretty cool when you think about it...

Judas · Oct 2, 2007, 10:12 PM

yep... that's what i like about dvi... and will moreso improve with Display port..

see i KNEW the 4 pins on the one side were for VGA..

but swimtech..

one other thing.

The dvi-d ports on my x1900's both provide a DVI-D connection (only way to run a dell 3007fpw @ 2560x1600)... and allow for DVI-VGA converters... as well with the 4 pins.....

so the only thing anyone should look out for is..

a DVI port on a video card that DOESN'T have those 4 pins around the one larger flat pin ..... cause if don't have that, you won't be able to use a standard DVI-VGA adapter.

swimtech · Oct 2, 2007, 10:48 PM

Quote:

Originally Posted by Judas

so the only thing anyone should look out for is..

a DVI port on a video card that DOESN'T have those 4 pins around the one larger flat pin ..... cause if don't have that, you won't be able to use a standard DVI-VGA adapter.

Yep, 'fraid not.

champ_status · Feb 6, 2012, 11:04 PM

I recently installed a ati radeon hd5450. I have a 20" LCD monitor (vga chord) which i connect to the gfx via a DVI to VGA adapter but i can't seem to get the default resolution of 1600x900 which i use to get before installing the gfx , it only allows me 1440x900 which doesn't look good for hd videos. I'm wondering if this is because of the adapter converting the digital signal to analog... any help?

**kris23** · Feb 7, 2012, 12:11 AM

Welcome to HH!

this seems to be an odd problem... i personally run displays on VGA with various ATi/AMD cards and do not see this sort of problem happen often.

However, there are a few ways you can try and go about this issue. First, there are two common ways of adjusting display resolution in windows 7, going to the Control Panel>Display>Adjust Resolution

This most likely was the method you used. with some card and monitor configurations, you can go to Advanced Settings and uncheck an option called "Hide modes that this monitor cannot display" which may help your situation.

Another method of adjusting your resolution is to go into your Catalyst Control Center, a control panel that comes with all ATi/AMD driver suites and go under "Desktop Properties."

Hopefully this option gives you more resolution options as it usually has more than the built in windows control panel. Hope your problem is resolved!

Dyre Straits · Feb 8, 2012, 07:03 AM

There have been a few instances when I was using the DVI->VGA adapter that I would need to Remove the current monitor/s from within Device Manager, reboot and let Windows re-detect the monitor and install the PnP drivers for it. It may also be necessary to check the manufacturer's website for any updated drivers for the monitor.

Sep 14, 2007, 08:34 AM	#1
johny_rotten DriverHeaven Newbie Join Date: Sep 2003 Location: Sierra Nevada Mountains, California Posts: 15 Rep Power: 0	DVI to VGA adaptor, any disadvantages ? I'm thinking about buying the Sapphire Radeon X1950Pro AGP, Newegg.com - SAPPHIRE 100171L Radeon X1950PRO 512MB 256-bit GDDR3 AGP 4X/8X HDCP Ready Video Card - Retail It has dual DVI out and I don't know much about what DVI is accept that's I think it's made for LCD displays. I still have my beloved Sony Trinitron CRT monitor. I'm just wondering if there are any disadvantages to using a CRT on the DVI out with the adaptor? I never run resolutions above 1280x1024 If anyone out there is using a CRT on the DVI out I'd like to know what they think. Thanks, Johny

Sep 15, 2007, 04:00 AM	#5
swimtech HardwareHeaven Extreme Member Join Date: May 2002 Location: North Carolina Posts: 4,040 Rep Power: 124 System Specs	You know, this is a great question that I don't remember ever really being asked... The answers you've gotten are good, and correct, but why? This surprised me a couple years ago... DVI is of course, Digital Video Interface, and is ideally suited for controlling digital technology based displays like LCDs and so forth. The high bandwidth, along with not having to convert the video data stream to an analog signal makes for the cleanest possible movement and display of the data. The light beamed from behind the digitally positioned LCDs to create color convert that digital stream from the video card to a frequency of light that your eyes can send to your brain. Voila, Sam gets Serious - with you! The surprise for me was finding out that the DVI-I connector has those four holes on the right - over and under the line shaped connector hole - that carry good ol' analog RGB, or VGA in other words. They um, hedged, no helped - yeah, that's the ticket! We still need VGA on there somehow so we'll give 'em four or five pins on our new connector (that's all that was ever really needed anyhow...) for VGA/Analog displays until they fade out. No, really though, it's difficult technically to transmit a high res analog VGA signal (1600x1200 or so, and up...) across wires of any kind or distance. Color information changes phase slightly, luminance loses its reference and changes amplitude, and more. And the circuitry needed to process that signal is expensive and inaccurate compared to processing/transmitting square waves with control bits in a digital video data stream. Quality and cost - that's why video is going digital, and has been for years. It's easier electronically to originate, process, and transmit at high resolution, and cheaper to manufacture - but I digress, sorry... The DVI-I connector's four holes can be routed through the adaptor to the VGA pins of your older monitor's cable without conversion or noticeable distortion at all - it's just a jumper to match the VGA cable. There's no active conversion or changing of the signal coming from the video card at all - and at the resolution at which you run your Good Ol' Sony (of your Owney - remember that commercial - no?) it will be just like coming off a standard VGA connector. __________________ It's not so much getting your way that matters or not - what matters is how you go about getting it. Last edited by swimtech; Sep 15, 2007 at 04:06 AM.

Sep 16, 2007, 04:54 AM	#10
Fig DriverHeaven Newbie Join Date: Jul 2007 Location: Kingston, MA Posts: 5 Rep Power: 0	Any time you convert a signal from digital (DVI) to analog (RGB) or vice versa you are going to get some signal loss. That said as the others have said you probably won't notice it. My system is very close to yours and I'm getting very poor performance. Let me know how you make out with the new card. Fig Last edited by Fig; Sep 18, 2007 at 01:41 AM.

Oct 2, 2007, 09:41 PM	#13
swimtech HardwareHeaven Extreme Member Join Date: May 2002 Location: North Carolina Posts: 4,040 Rep Power: 124 System Specs	Hey all, I found this that explains what matters when dealing with the differing DVI type connectors rather simply. A DVI-D connector cannot be adapted for an analog VGA cable without active conversion circuitry because the analog signal does not exist via that connector. The single link DVI cable is missing 6 pins in the center. The dual link DVI connector has pins all the way across. You can have single link or dual link cables in either DVI-I or DVI-D varieties. The video digital to analog conversion is done on the video card, then routed to the four pins on the DVI-I connector (or to a VGA connector). D/A conversion of digital computer video has been being done for a very long time (ever noticed the RAMDAC specs for video cards all these past years - that's the frequency of the video digital to analog converters - the higher the better) and is quite mature. The same type of conversion is done in DVD players for output via composite, component, or S-video outputs. So, it should be apparent that eliminating the RAMDACS on the video card and providing only digital output to a monitor via a DVI-D connector should be cheaper for the manufacturer. It decreases flexibility for us users, but should (theoretically...) provide the highest quality output because there are no conversion losses or artifacts - tiny though they are... High res VGA looked pretty good for the past decade or so didn't it? From the more than you probably wanted to know department - think about this... Basically, the D/A conversion still happens, but only once. The conversion has moved out of the video card, down the cable, into and through the monitor, all the way to the display panel itself. The LCDs themselves serve to convert the digital video data to analog light waveforms (with the assistance of the backlight in an LCD display) for perception by your eyes. A ton of circuitry and processing have been eliminated by keeping the video digital all the way to the panel. Pretty cool when you think about it... __________________ It's not so much getting your way that matters or not - what matters is how you go about getting it. Last edited by swimtech; Oct 2, 2007 at 10:49 PM.

Feb 6, 2012, 11:04 PM	#16
champ_status HardwareHeaven Newbie Join Date: Feb 2012 Posts: 1 Rep Power: 0	Re: DVI to VGA adaptor, any disadvantages ? I recently installed a ati radeon hd5450. I have a 20" LCD monitor (vga chord) which i connect to the gfx via a DVI to VGA adapter but i can't seem to get the default resolution of 1600x900 which i use to get before installing the gfx , it only allows me 1440x900 which doesn't look good for hd videos. I'm wondering if this is because of the adapter converting the digital signal to analog... any help?

Sep 14, 2007, 09:17 AM	#3
Just Learnin' HardwareHeaven Senior Member Join Date: Nov 2005 Location: Winnipeg, Manitoba, Canada Posts: 1,414 Rep Power: 56 System Specs	Works fine on my Sony G520. The only thing that looks weird is the ASUS logo on the mobo boot screen before it carries on to boot into windows.

Sep 15, 2007, 06:14 AM	Thread Starter #7
johny_rotten DriverHeaven Newbie Join Date: Sep 2003 Location: Sierra Nevada Mountains, California Posts: 15 Rep Power: 0	Thanks for the replies, and thanks Swimtech for clear and to the point explanation of how DVI works an why it makes sense. I'm ordering the Sapphire Radeon X1950Pro AGP right now. Johny

Sep 15, 2007, 07:54 AM	#8
aNy_oNE DriverHeaven Lover Join Date: Nov 2006 Posts: 162 Rep Power: 0 System Specs	Yeah, thank you for that :P I will be upgrading soon but keeping this CRT monitor, so that's nice to know.

Feb 7, 2012, 12:11 AM	#17
kris23 Going Insane..... Join Date: Dec 2006 Location: Los Angeles Posts: 6,013 Rep Power: 131 System Specs	Re: DVI to VGA adaptor, any disadvantages ? Welcome to HH! this seems to be an odd problem... i personally run displays on VGA with various ATi/AMD cards and do not see this sort of problem happen often. However, there are a few ways you can try and go about this issue. First, there are two common ways of adjusting display resolution in windows 7, going to the Control Panel>Display>Adjust Resolution This most likely was the method you used. with some card and monitor configurations, you can go to Advanced Settings and uncheck an option called "Hide modes that this monitor cannot display" which may help your situation. Another method of adjusting your resolution is to go into your Catalyst Control Center, a control panel that comes with all ATi/AMD driver suites and go under "Desktop Properties." Hopefully this option gives you more resolution options as it usually has more than the built in windows control panel. Hope your problem is resolved! __________________ Hardwareheaven Super-Moderator Building a new computer system and not sure where to start? Click Here! last updated (5/18/11) Rosewill FUTURE case replaces CM 690 II with its greater interior length. Building a PC: Step by Step Guide Written by Kristopher Pedemonte and Nathan Marks-Forder Edited by Allan Campbell Questions or Comments? feel free to post them in the forums!