What is the difference between passive and active?

[zcarm]

I am trying to get three monitors on my msi gtx 970 oc edition and I am looking for adapters (trying to use the hdmi, a dvi-i to vga, and a dvi-d to vga) but i keep finding a whole bunch of specs on adapters as active or passive. What is the difference? Which one do i need?

 

[kanewolf]

hdmi and dvi-d are both digital output ports. You will need an active adapter for those two ports to convert digital to analog. The dvd-i has analog AND digital output so you can use a passive adapter for that port.

 

[Wolfshadw]

Active means taking a digital signal (DisplayPort, HDMI, DVI-D) to an analog signal (VGA, DVI-I)
Passive means taking a digital signal (DisplayPort, HDMI, DVI-D) to another digital signal (DisplayPort, HDMI, DVI-D) or an analog signal (DVI-I, VGA) to another analog signal (DVI-D, VGA).

Note DVI-I has both digital and analog signals "I"ntegrated.

Your DVI-D to VGA would require an active adapter.

-Wolf sends

 

[Pinhedd]

I am trying to get three monitors on my msi gtx 970 oc edition and I am looking for adapters (trying to use the hdmi, a dvi-i to vga, and a dvi-d to vga) but i keep finding a whole bunch of specs on adapters as active or passive. What is the difference? Which one do i need?

Hi,

A passive adapter is an adapter that contains no powered components. In most cases, a passive adapter simply rearranges the pinouts and provides two different mechanical interfaces.

An active adapter is an adapter that contains powered electrical components that are used to convert the signal format.

The following passive conversions are possible because the formats are electrically compatible:

VGA -> DVI-A

DVI-A -> VGA

DVI-I -> VGA

DVI-I -> DVI-A

DVI-I -> DVI-D

DVI-I -> HDMI (HDMI enhancements may not be enabled)

DVI-D -> HDMI (HDMI enhancements may not be enabled)

HDMI -> DVI-D

The following are special cases. They are technically actively converted, but the DisplayPort controller contains the converter built in.

DisplayPort -> DVI-D

DisplayPort -> HDMI

The following conversions must be performed using an active converter:

VGA -> DVI-D

VGA -> HDMI

VGA -> DisplayPort

DVI-A -> DVI-D

DVI-A -> HDMI

DVI-A -> DisplayPort

DVI-D -> VGA

DVI-D -> DVI-A

DVI-D -> DisplayPort

HDMI -> VGA

HDMI -> DVI-A

HDMI -> DisplayPort