[SOLVED] Would a DVI to VGA adapter work both ways?

eternalabys

Commendable
Nov 8, 2018
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So, this might be a stupid question,
but I'm wondering if it were possible to use a DVI to VGA adapter backwards and forwards, considering there is no logic in the adapter it should work.

But I'm worried because I recently got an MSI GTX 760 as a hand-me-down GPU and was wondering if I could do a dual monitor setup, my main one having a displayport running in to it and another having a DVI to VGA (or vice versa, VGA to DVI) adapter running from the card in to a second VGA monitor.

The adapters are cheap but that would still be money wasted.

Image of what the adapter looks like:

https://ibb.co/486QPL5
 

bignastyid

Titan
Moderator
A passive DVI-I to VGA only works without a converter/active adapter because DVI-I has both a Digital and an Analog signals so the adapter just takes the pins for the analog signal from the DVI-I port and converts them to the VGA(also analog) pinout. However DVI-D is digital only(has no analog signal) and requires an active adapter/converter.

The picture is kind of a poor one but looks like a standard passive DVI-I to VGA adapter, so if the gpu has a DVI-I port and the monitor has a VGA port then it should work.

While technically a DVI-I to VGA adapter can work both ways, most monitors use DVI-D not DVI-I so it will not work on those.
 
No, it does not.
  • DVI is digital interface, VGA is analogue
  • The way DVI GPU talks to VGA monitor by means of "adapter" is just because most DVI GPU ports also provide necessary signals on the connectors for VGA monitors to work.
  • VGA GPU to DVI/HDMI/DP monitor needs special active cable, making it tricky, and generally not worth.
 

bignastyid

Titan
Moderator
A passive DVI-I to VGA only works without a converter/active adapter because DVI-I has both a Digital and an Analog signals so the adapter just takes the pins for the analog signal from the DVI-I port and converts them to the VGA(also analog) pinout. However DVI-D is digital only(has no analog signal) and requires an active adapter/converter.

The picture is kind of a poor one but looks like a standard passive DVI-I to VGA adapter, so if the gpu has a DVI-I port and the monitor has a VGA port then it should work.

While technically a DVI-I to VGA adapter can work both ways, most monitors use DVI-D not DVI-I so it will not work on those.
 

eternalabys

Commendable
Nov 8, 2018
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Thank you for your responses,
I've checked the GTX 760 and it has both DVI-I and DVI-D interfaces,
As I understand it, I need to buy a DVI-I to VGA adapter to make my secondary monitor work, correct?
 

Krotow

Commendable
Oct 2, 2019
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In short:

DVI-I (large flat pin at bottom with 4 small pins in rectangular shape around it) to VGA and vice versa works in both directions. This is passive connection with only wires connected to appropriate connector pins at both sides.

DVI-D (small flat pin at bottom without other pins around it) have active unidirectional adapter at one side. Works only in single direction. Use separate DVI-D to VGA adapter for DVI -> VGA connection. And VGA to DVI-D adapter for VGA -> DVI connection.
 

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