Below are real-time benchmarks from our own machines. You can view the instructions for making here or on the Install page.
Compare your performance with ours. We also encourage you to send us your benchmarks. That way, we can build a comprehensive list of what performance can be expected from what hardware.
Go to the base of the RTXI directory you cloned from GitHub and run:
This script will test kernel latencies at rate of 10 kHz while under stress. The test lasts 30 minutes. If at any point you need to stop the test, you can kill the process by entering
CTRL+c in the terminal running the stress test. Then, run
pkill stress. If you forget to use
pkill, the system will stop measuring latencies, but it will still be under stress. Depending on your system, you may experience lag in your desktop during the test. Keep in mind that the stress test is designed to assess real-time performance under worst-case conditions. If your system performs well under heavy load, you can be reassured that it will perform well during your experiments.
Once completed, the script will generate a histogram of latencies. You can view it from the command line with the image viewer, eog (Eye of GNOME). Run:
For systems with discrete graphics cards and somewhat recent processors, latencies should consistently remain on average below 2-3 μs. Worst case latencies may get as high as 20-30 μs, but keep in mind that these spikes occur often once or twice over the 30 minute duration of the stress test, which at 10 kHz constitutes 18 million cycles. A histogram of latencies will be generated at the end of the test, so you see can how often high latencies occur. Compare your performance to what is available on our stats and benchmarks page and let us know if your performance is problematic.
Record the RT Benchmarks module in RTXI using the Data Recorder module. RT Benchmarks displays runtime statistics for your system, such as the computation time, real-time period, and jitter. For those unfamiliar with the terms, here are brief definitions:
To record the RT Benchmarks module:
Note: You can change the frequency for your measurements via the System Control Panel. Just open the module, change the value for "Frequency," and hit "Apply" to save your changes.
Note: If you set the frequency high or record for a long time, the size of the generated files can become unwieldy. Make liberal use of the downsampling functionality in the Data Recorder.
Open up a terminal and move to your RTXI directory. In the
scripts/dev/ folder, you will find a script called
plot_rtxi_performance. This script will extract the performance data from an HDF file and plot it using R. To run it, do:
FILENAME is the name of the *.h5 file you generated with the Data Recorder. Compare your output with ours, and let us know if you are having performance issues.