This is one of the things I still miss about BeOS. On late 90s hardware, the OS wasn't quite hard real-time like QNX but the worst-latency latency was much better than Windows 10 or MacOS on the latest hardware, even in the presence of heavy resource contention — I remember simultaneously surfing the web, downloading video from a camcorder with a Firewire interface which did not buffer, and compiling Mozilla. The UI latency didn't change at all, and the DV transfer didn't drop a packet — everything else got throttled back as necessary, of course, but that meant that, say, GCC took longer to run rather than impacting what I was doing in the foreground.