A collection of Mac command line commands to measure cpu speed, throttling etc
The best I've seen to measure cpu metrics is the Intel Power gadget (though not a command line utility). It's from Intel so it's supposedly trustworthy.
There are some ways to get metrics from the command line, though they do not offer the details and accuracy of the Intel power gadget.
pmset -g therm # sample output # 2019-11-24 15:12:28 +0100 CPU Power notify # CPU_Scheduler_Limit = 100 # CPU_Available_CPUs = 8 # CPU_Speed_Limit = 100
sysctl hw.cpufrequency # sample outout, 2.2 ghz processor # hw.cpufrequency: 2200000000