I tested my own system using Bruce's "measure_interval.cpp" program (on Windows 1909): - Slack (sometimes) sets the global timer to 1ms when it is in the foreg

I tested my own system using Bruce's "measure_interval.cpp" program (on Windows 1909): - Slack (sometimes) sets the global timer to 1ms when it is in the foreground, but restores it in background - Spotify sets the global timer to 1ms, no matter what. Even if it isn't playing. - Skype sets 1ms, if started at Startup (which it defaults to), even though I am logged out and it just has a tray icon. But when I manually start it, it doesn't (always) set it to 1ms. - VSCode will set it to 1ms when you are interacting with it, but will eventually revert to 15.6ms if left alone (even if it is still in foreground). - Firefox doesn't appear to set it (on its own; I presume that if I opened a tab that was using a low setTimeout or requestAnimFrame it might). Spotify is interesting. A lot of people probably have that app, and since it sets 1ms unconditionally, it would have been setting fast-timer mode prior to the 2004 update, which could inadvertently "speed up" whatever games people were running. That includes my own game, which uses a foreground sleep of as low as 1ms to try to hit its time target, and I don't call timeBeginPeriod. I guess I'll find out when I get the 2004 update.