It is likely realized when attempting to run larger scale tests with artillery.io that high CPU warnings will be displayed. As this technology runs a node process to drive test scenarios defined in yaml scripts, the single-core process can attempt to push so much throughput before lacking in CPU resources. A quick Google search will bring about the following result describing some features within artillery to distribute artillery scenarios across multiple cores, https://artillery.io/blog/artillery-20-preview-multicore, but unfortunately does not seem to be the case...
By checking the test cases here. The way to enable the feature: e.g. MULTICORE=1 ARTILLERY_WORKERS=4 followed by the rest of the command to run your artillery test.