Overdrive option in Monitor settings.

[Cyberspirit]

Hey, I was looking around in my monitor's settings and, I found a setting called "overdrive" I got curious so, after looking around for a while I found this article by bit-tech about LCD overdrive and it's downsides.

 

I have an AOC I2481FXH that has an IPS panel so I wasn't sure if the downsides still apply to it.

Though, I'd assume they do.

[ShredBird]

Yes, overdrive will still have the same effects on an IPS panel.  I have a new 144 Hz Dell monitor that is overdriven, but it has two modes "Normal" and "Fast".  Normal has some ghosting but it's very minimal and I only notice it when my mouse cursor passes over very specific colors.  With the setting set to "Fast" ghosting becomes much more noticeable, but I like having the option.  In shooters at 120+ fps having it to "Fast" mode the monitor maintains clarity in motion better and I don't notice ghosting in gaming as much as I do in the Windows desktop.

Overdrive is a normal consequence of using an aggressive control scheme, inverse ghosting is an artifact of overshoot and is an understood part of control theory.  I don't see it as a flaw, but simply an engineering trade off.  Now, whether or not your monitor manufacturer used that tradeoff intelligently is a different story.  I think Dell in my case did a good job by offering two modes.

Do you notice any artifacts from overdrive that bother you?  If not, I wouldn't worry about it too much.

[Cyberspirit]

Thanks for the answer

5 hours ago, ShredBird said:

Do you notice any artifacts from overdrive that bother you?  If not, I wouldn't worry about it too much.

Honestly, I'm not sure what I should look for.

[ShredBird]

8 hours ago, Cyberspirit said:

Thanks for the answer

Honestly, I'm not sure what I should look for.

In an LCD, there are little crystals that align to an applied electric field (voltage).  Depending on how much voltage is applied the crystals will allow some fraction of light to pass through to your eye.  These crystals are physical things that have to move, so naturally it takes some time to do it.  Overdrive applies more voltage than is needed to get the crystals to move as fast as possible, sometimes the crystals are moving so fast that they don't stop at the desired position, they pass it a little bit and then have to be moved back some.  The side effect of this is that for a brief moment, the pixel is displaying the wrong color as it back tracks to the correct value.

This image shows what overdrive is from a control theory standpoint.  The 1 line is the position the crystals need to be in to display the proper color, the red line is how the crystal moves over time to get there when overdrive is enabled, as opposed to the blue or green line that would be used typically.  Notice how the red line gets to 1 quicker than the green line.  That's why overdrive is used at all, because even though it overshoots the correct value, it gets to it faster than if you didn't.

The pixels displaying the wrong color are anywhere there are large changes in color.  For example, on my monitor under fast mode, if I drag my mouse cursor across a bluish-gray background, it appears to have a purple shadow following it.  That's because the pixels that were white to display my mouse pointer are trying to change to that bluish-gray color as fast as possible and they overshoot and display purple before settling on the correct color.  This is referred to in the community as "inverse ghosting" as the shadow can sometimes follow the moving object or anticipate its movement and the color often looks wrong like an inverted color image.

A quick image search found this:

 

See how as the window is dragged around the monitor is displaying a purple color?  That's inverse ghosting.  Try dragging windows quickly across your desktop with overdrive on and off and try changing your background to different solid colors, see if you can notice a difference.
 

[Cyberspirit]

10 minutes ago, ShredBird said:

Spoiler

 

In an LCD, there are little crystals that align to an applied electric field (voltage).  Depending on how much voltage is applied the crystals will allow some fraction of light to pass through to your eye.  These crystals are physical things that have to move, so naturally it takes some time to do it.  Overdrive applies more voltage than is needed to get the crystals to move as fast as possible, sometimes the crystals are moving so fast that they don't stop at the desired position, they pass it a little bit and then have to be moved back some.  The side effect of this is that for a brief moment, the pixel is displaying the wrong color as it back tracks to the correct value.

This image shows what overdrive is from a control theory standpoint.  The 1 line is the position the crystals need to be in to display the proper color, the red line is how the crystal moves over time to get there when overdrive is enabled, as opposed to the blue or green line that would be used typically.  Notice how the red line gets to 1 quicker than the green line.  That's why overdrive is used at all, because even though it overshoots the correct value, it gets to it faster than if you didn't.

The pixels displaying the wrong color are anywhere there are large changes in color.  For example, on my monitor under fast mode, if I drag my mouse cursor across a bluish-gray background, it appears to have a purple shadow following it.  That's because the pixels that were white to display my mouse pointer are trying to change to that bluish-gray color as fast as possible and they overshoot and display purple before settling on the correct color.  This is referred to in the community as "inverse ghosting" as the shadow can sometimes follow the moving object or anticipate its movement and the color often looks wrong like an inverted color image.

A quick image search found this:

 

See how as the window is dragged around the monitor is displaying a purple color?  That's inverse ghosting.  Try dragging windows quickly across your desktop with overdrive on and off and try changing your background to different solid colors, see if you can notice a difference.

 

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I tried this and, I couldn't notice anything so, I guess that's good.

My main concern about Overdrive was that in the article they said that it could increase input lag.

[ShredBird]

1 minute ago, Cyberspirit said:

I tried this and, I couldn't notice anything so, I guess that's good.

My main concern about Overdrive was that in the article they said that it could increase input lag.

Interesting, I've never encountered or noticed that personally.  I guess the good news is that the AOC seems to have implemented it pretty conservatively.

[Cyberspirit]

1 minute ago, ShredBird said:

Interesting, I've never encountered or noticed that personally.  I guess the good news is that the AOC seems to have implemented it pretty conservatively.

 

Maybe my eyes aren't good enough to spot it?

I tried every solid color wallpaper with Overdrive set to strong but, I didn't see any unusual colors.

[ShredBird]

4 minutes ago, Cyberspirit said:

Maybe my eyes aren't good enough to spot it?

I tried every solid color wallpaper with Overdrive set to strong but, I didn't see any unusual colors.

That or it's just really really subtle, which is a good thing.

[Cyberspirit]

7 minutes ago, ShredBird said:

That or it's just really really subtle, which is a good thing.

Any ideas if it causes any input lag?

Btw. Thanks for all the help so far.  

[ShredBird]

From an engineering standpoint, I can't think of a single reason why employing overdrive would introduce input lag.  It doesn't appear that the article you posted offers an explanation either.  They compare a Dell monitor to a Samsung monitor and conclude that the Samsung lags the Dell.  But, that doesn't prove that overdrive creates input lag, that just proves that the display scaler chip the the Samsung uses takes longer to process images than the Dell scaler.  I think for this article to claim that input lag is related to overdrive is downright misleading and erroneous.

And you're very welcome!