Is it possible to set custom CPU throttling in Chrome DevTools?

I am using Google Chrome 63.

In DevTools in Performance tab there are three CPU throttling settings: “No throttling”, “4x slowdown” and “6x slowdown”.

Is it possible to set custom throttling, for example “20x slowdown”? It could be via setting some flag in chrome.exe file or programmatically via NodeJS library.

I found that Lighthouse library has kind of helpful function but if I change the default value inside it (CPU_THROTTLE_METRICS seems to be equal to 4) from 4 to (for example) 20 and run it, how can I be sure it really is 20x slowed down?

Also, I would like to know, if it is possible to do such simulated “slow down” to the GPU in similar way?

Thanks for any advice.