Blur Busters Forums

Hello,

I’d like to reduce the input lag on my GB3461WQSU monitor, which I haven’t calibrated. I’m measuring input lag by duplicating the displays in Windows 11 and running a stopwatch on estopwatch. net at my laptop’s native resolution, which is Full HD.
The laptop is a Dell G15 with an RTX GPU.
I’m not sure whether my HDMI cable is 2.1 or 2.0.

In about half of the photos the time is identical, and in the other half it’s higher by more or less 50 ms (which is crazy in my opinion). I also feel slight differences in games, although only in the stats (maybe placebo?), since the image has never shown any smearing and looks razor‑sharp.

1) Is this a good measurement method?

2) Is estopwatch. net reliable, or do I need some dedicated application?

I’d like to know whether I’m measuring this correctly and whether the input lag can be reduced.

Best regards!

IIRC, this is not a good method, because the duplication itself can introduce the time difference. However, you should be able to test this by switching the displays and make the other one the primary display. If you now observe the same result (50ms higher on the clone), then it's the cloning that's the issue, not the display.

Unfortunately estopwatch. net needs manual start so I cannot compare the times.
I could extend displays and start estopwatch on two tabs separately and estimate the delta to check if it is the same across lets say 10 photos. Let me do this then.

So I have extended the displays (not duplicate as you suggested).
I have started the timer on one display and then on the second display.
I have made 10 photos and calculated the delta.
Because I have started it manually the delta is big naturally.
The times are as follows:
- 924ms
- 924ms
- 924ms
- 862ms
- 925ms
- 863ms
- 926ms
- 922ms
- 924ms

So the delta is almost equal on all photos but the are two photos with the much lower delta (862ms and 863ms) which indicates that the input lag is different by the ~50ms.

Why use photos? Record a video instead and they go through the video one frame at a time.

Also, why are you starting the stopwatch twice? I thought you are duplicating the display, so the second display shows whatever the first one is showing.

RealNC wrote: ↑

01 Feb 2026, 12:02

[...]I thought you are duplicating the display[...]

At first I was duplicating the displays but you have said:

RealNC wrote: ↑

01 Feb 2026, 11:25

IIRC, this is not a good method, because the duplication itself can introduce the time difference[...]

So I'm not duplicating but extending the display because as you said the duplication itself can introduce the time difference.

RealNC wrote: ↑

01 Feb 2026, 12:02

Why use photos?[...]

It makes no difference between photos and video because either way I would compare frames on the video

So the question would be what is the best setup to compare input lag?
I don't have CRT display unfortunately.

PaTera wrote: ↑

01 Feb 2026, 12:14

So I'm not duplicating but extending the display because as you said the duplication itself can introduce the time difference.

You can test duplication by doing one test and then another with the displays swapped to see if duplication has an effect.

So the question would be what is the best setup to compare input lag?

Probably an active HDMI video splitter that is known to have the same latency for both outputs. But then again, you aren't testing TVs, but high-refresh rate monitors. So... no idea, really

What I'd try is test display cloning/duplication mode separately to find out if the cloning adds latency to the second display.