There are many different tools available to measure the realtime performance of a system.

The cyclictest is the simplest and most usefull benchmark.

Standard tool to measure the maximum jitter of a system.

Cyclictest

The following things can influence the real-time behaviour:

• CPU
  • Mobile x86 CPU (with suffix like U, Y and M i.e i7-4600U) seems to perform much worse than non-mobile processors. Mobile processer add about 100us-200us jitter.
  • ARM processer seem to have about 60us max jitter and a high medium jitter
• Kernel version
  • 4.4.169-rt177 seems to be better than 4.19.15-rt12
• BIOS settings
• Some drivers, like WiFi driver, may negatively influence latency

At first, test the most basic system possible. With this test, you can get a baseline of the best possible real-time performance of the hardware. Every feature added will make the system more complex and add more stuff, which can increase jitter.

With this approach you can get a feeling which performance is possible and which part of the system is responsible for a high jitter.

1. Test hardware, BIOS settings and kernel version
2. Test full distro in text mode
3. Test full distro in graphical mode
4. Test full distro under load