Plan a load test
Back3. What that would mean
One pass takes
21.28s
median of 3 past run(s)
Projected passes
84
8.4/min
Each user does
28
passes in the window
about 84 passes if the application keeps up at 21.3s each; fewer means it slowed down, which is the result you are looking for
This machine: 15.8 GB RAM and 4 CPU(s): ~400 MB per browser leaves room for about 12 at once.