If you want to see the effect of the real-time kernel, build and run the cyclictest utility from the Linux Foundation.<p><a href="https://wiki.linuxfoundation.org/realtime/documentation/howto/tools/cyclictest/start" rel="nofollow">https://wiki.linuxfoundation.org/realtime/documentation/howt...</a><p>It measures and displays the interrupt latency for each CPU core. Without the real-time patch, worst case latency can be double digit milliseconds. With the real-time patch, worst case drops to single digit microseconds. (To get consistently low latency you will also have to turn off any power saving states, as a transition between sleep states can hog the CPU, despite the RT kernel.) Cyclictest is an important tool if you're doing real-time with Linux.<p>As an example, if you're doing processing for software defined radio, it's the difference between the system occasionally having "blips" and the system having rock solid performance, doing what it is supposed to every time. With the real time kernel in place, I find I can do acid-test things, like running GNOME and libreoffice on the same laptop as an SDR, and the SDR doesn't skip a beat. Without the real-time kernel it would be dropping packets all over the place.