gtmetrix.com
https://tools.pingdom.com/
https://developers.google.com/speed/pagespeed/insights/
from above tools you can get performance of website and server as well as suggestion from server end as well code end needed to boost up the website, although there are multiple factors which affects speed of website.
1. server location
2. server resources like ram and cpu and type vps , shared or dedicated
3. web server
4. web server caching
5. filesystem caching
6. database version and optimisation for best speed and performance
7. website page size and website code end optimisation
8. SSD disk or disk type like raid
9 . SSD Disk I/O rate
10. cdn etc
these techniques can be implement on all control panels , plesk provide by default nginx caching , these can be achieved on free control panel as well
so with only control panel you will not get speed , all above factors should be considered to achieve speed .