Faster refresh rate in 1.22 vs. 1.21

[skius]

TL;DR: What changes happened between 1.21 and 1.22 that would make a raw mode application render faster than at 60hz?

I am working on a small game with real time graphics in the terminal, and I've mostly been using Windows Terminal 1.21 to develop it. Something I've noticed is that despite my engine being capable of pushing 'frames' at well above 144 fps, it didn't feel any different when locked to just 60 fps on my 144hz monitor. I confirmed this by capturing the screen at a high refresh rate and stepping frame by frame through the footage. My program runs in raw mode and flushes the terminal buffer once per frame when everything has rendered.

To investigate, I wrote a little program that just spams lines with a moving character to the terminal in default mode, and noticed that it was significantly smoother (which I again confirmed via video capture), leading me to build Windows Terminal locally and trying to see if I could remove some limits and make my game run faster in raw mode. To my surprise things were already faster without any changes, which I double checked as well in the MS Store preview 1.22 build, so now I am quite curious what changed?

I didn't see anything in the release notes, and git blaming the function I was initially eyeing to change (RenderEngineBase::WaitUntilCanRender) didn't tell me more either.

And just to be clear, I love that change, thanks! 😄

(PS: I am not entirely sure about 'raw mode' being the defining factor here)