What’s the difference between windowed and borderless window in terms of input lag?

I’ve looked at this myself, and it depends on quite a few factors. Usually, borderless has less input lag than windowed, because it doesn’t need to go through the desktop compositor (saving a few milliseconds). But that may not make much difference for most gamers – playing poker or slots is not the same as playing a first-person shooter.

Others insist that disabling borderless windowed mode reduces latency. But I think that drivers and GPU utilization have far more impact on real-world input latency. For those who are really on the hunt for every possible millisecond, I would suggest testing both modes to see how they feel subjectively. Ultimately, I’m sticking with whatever is easier on the eyes and works better with my windows management.

Borderless window should also provide a more fluid experience, as well as lower input latency. The graphics card is used a bit more efficiently, and fewer scaling operations are required than with a standard window. Some gamers prefer it for twitchy action titles; others disagree. If your system is under heavy load from other applications, however, you may not notice a significant improvement. Just try it out and decide which one works best for you.

Borderless window is generally good, perhaps 1-2 ms better than windowed because it reduces the amount of time switching from the OS to the game (the OS could be doing things while your game is not in focus). This would matter if you were trying to maximize your win rate on an online poker or slot machine. Some people prefer one or the other, I use borderless most of the time for fast paced 3D action.

This also lowers input latency slightly compared with windowed mode (because there are no additional operations needed to render a window border). This could be important in fast-action games such as poker or slot machines, but in reality, it makes only a minuscule difference. Nevertheless, lots of PC gamers seem to like it, so try it out!