VT Tweak on 144hz

[muzadull]

Does VT tweaks works on 144hz and how to check that?
My understanding is that increasing this value decreases input lag.
I increased my monitor's vertical total to 1500 and it seems to work even at 144hz.
Monitor:Viewsonic XG2401 (Connected Via Display Port)

[RealNC]

VT increases are used to tweak cross-talk when using strobing (blur reduction modes). They are also used to lower input lag when using a low Hz mode (like 60Hz) on a high Hz, non-VRR display (you can get 144Hz scanout speed while using 60Hz, for example.)

In your case, raising the VT does indeed lower input lag a bit, but probably not by much. The scanout time at 144Hz is 6.9ms. If you double the VT, the scanout speed is halved, which is 3.5ms. The average input lag reduction is half of that: 1.7ms. However, I can assume that you are not doubling the VT. That would be way out of spec for a 144Hz display.

What's the original VT? By knowing that, you can calculate what latency reduction you get by increasing it to 1500.

[Falkentyne]

VT increases are used to tweak cross-talk when using strobing (blur reduction modes). They are also used to lower input lag when using a low Hz mode (like 60Hz) on a high Hz, non-VRR display (you can get 144Hz scanout speed while using 60Hz, for example.)

In your case, raising the VT does indeed lower input lag a bit, but probably not by much. The scanout time at 144Hz is 6.9ms. If you double the VT, the scanout speed is halved, which is 3.5ms. The average input lag reduction is half of that: 1.7ms. However, I can assume that you are not doubling the VT. That would be way out of spec for a 144Hz display.

What's the original VT? By knowing that, you can calculate what latency reduction you get by increasing it to 1500.

Was never aware you could reduce input lag on a 60hz display by doing this.
I still wonder how much the video card will factor into the input lag, though. Usually the video card/drivers have a larger effect on input lag than the monitor.

[muzadull]

VT increases are used to tweak cross-talk when using strobing (blur reduction modes). They are also used to lower input lag when using a low Hz mode (like 60Hz) on a high Hz, non-VRR display (you can get 144Hz scanout speed while using 60Hz, for example.)

In your case, raising the VT does indeed lower input lag a bit, but probably not by much. The scanout time at 144Hz is 6.9ms. If you double the VT, the scanout speed is halved, which is 3.5ms. The average input lag reduction is half of that: 1.7ms. However, I can assume that you are not doubling the VT. That would be way out of spec for a 144Hz display.

What's the original VT? By knowing that, you can calculate what latency reduction you get by increasing it to 1500.

Original VT is 1157.
~350 is not much.
Thank you for your explanations.

[RealNC]

Was never aware you could reduce input lag on a 60hz display by doing this.

Not on 60Hz displays. Only on non-VRR high refresh rates displays running at 60Hz (VRR displays don't need this.) A 144Hz display for example can run a high VT at 60Hz, giving it the scanout speed of 144Hz at 60Hz. Normally, 60Hz scanout speed is 16.7ms, but with a high VT, you can increase the speed to 6.9ms. That's an improvement of 9.7ms, with an average latency decrease of 4.7ms. Of course the usefulness of this is rather limited, since there's not many occasions where you'd run a high Hz display at 60Hz. But if you do, then the VT increase will help a bit.

I still wonder how much the video card will factor into the input lag, though. Usually the video card/drivers have a larger effect on input lag than the monitor.

The VT increase will decrease the scanout time by 9.7ms regardless of any other factors.