HD 6850 DVI-to-VGA

[michaelr87]

I run three monitors, all of which are VGA and I purchased a Powercolor HD 6850 with the intent of doing triple eyefinity. I was able to get the top DVI port to convert to VGA, as well as the DisplayPort, however the bottom DVI port will not convert to DVI. I have tried various different DVI-to-VGA adapters with no success. I tried the port with a DVI monitor using a straight DVI cable and it worked, so there is nothing wrong with the DVI. Anyone have an idea as to why the DVI-to-VGA adapter won't work in that port?

Thanks,

Michael

 

[gedrean]

I run three monitors, all of which are VGA and I purchased a Powercolor HD 6850 with the intent of doing triple eyefinity. I was able to get the top DVI port to convert to VGA, as well as the DisplayPort, however the bottom DVI port will not convert to DVI. I have tried various different DVI-to-VGA adapters with no success. I tried the port with a DVI monitor using a straight DVI cable and it worked, so there is nothing wrong with the DVI. Anyone have an idea as to why the DVI-to-VGA adapter won't work in that port?

Thanks,

Michael

I've had problems like this in the past with other cards. I'm guessing you tried the same DVI-VGA adapter and monitor that worked on the top port in the bottom port, and it was unable to work in the bottom port?

Some card manufacturers, to cut corners, will only have one of the DVI ports actually output the analog video data, the other port has the pins (or holes) for analog video but does not actually carry the analog data.

DisplayPort's standard I think requires that analog data be available, while in DVI the port can be DVI-I (both) and not carry the analog data, and still be compliant with the standard.

Seriously though, 3 Eyefinity using VGA? Painful in my head.

 

[rmerwede]

One of the DVI ports is not compatible with VGA (single or dual-link, not sure which; you have one of each). That's why is works with a DVI to DVI cable. If you have the card I think you do, only one DVI port says VGA next to it.

 

[larkspur]

I run three monitors, all of which are VGA and I purchased a Powercolor HD 6850 with the intent of doing triple eyefinity. I was able to get the top DVI port to convert to VGA, as well as the DisplayPort, however the bottom DVI port will not convert to DVI. I have tried various different DVI-to-VGA adapters with no success. I tried the port with a DVI monitor using a straight DVI cable and it worked, so there is nothing wrong with the DVI. Anyone have an idea as to why the DVI-to-VGA adapter won't work in that port?

Thanks,

Michael

Sounds like it is a DVI-D port meaning digital only. If your card has another displayport you could get another DP -> VGA adapter.

 

[larkspur]

DisplayPort's standard I think requires that analog data be available, while in DVI the port can be DVI-I (both) and not carry the analog data, and still be compliant with the standard.

Seriously though, 3 Eyefinity using VGA? Painful in my head.

DVI-I (regardless of single or dual-link) carries both digital and analog. DVI-D is just digital. So if the port is advertised as DVI-I then it wouldn't be compliant if it didn't carry an analog signal.

 

[gedrean]

larkspur is correct on this, I was mistaken. Anyhow, check if the blade has 4 contacts around it, if it does it's an incompliant DVI-I port, if not, it's a DVI-D and won't do Analog.

 

[michaelr87]

Alright, thanks guys. I ordered a new monitor with DVI input that is otherwise identical to my current monitors. @gedrean - what is wrong with triple eyefinity using VGA? VGA is fully capable of full 1080p on each monitor and even side-by-side you likely wouldn't even see the difference between DVI and VGA. I got a good deal on three identical VGA input only monitors so I went with it.

 

[gedrean]

I never liked the appearance of VGA with higher than 1280x1024 resolutions. I can see the fuzziness.

 

[michaelr87]

Best answer selected by michaelr87.

 

[Mousemonkey]

This topic has been closed by Mousemonkey