how to find sites on a particular hosting provider
 

I want to test load times of some sites on a particular hosting provider. How do I find out who's hosted there without asking.

How can I test or find out about their actual uptime without asking.

How can I find their speed, without asking.

Find out as many IPs as you can and then go to whois.sc and do a backwards lookup on the IPs.

Actual uptime would be more difficult. Open a cheap vituel account and test with a script yourself maybe.

Difficult ...

As said above, you need to find all IP's in use... can be 50, 100 on a single box if a shared one ( virtual accounts ). And they are not necessarely in numeric order ...

A dedicated is easier, since most have 5 or 7 ip's.