Like almost everybody does, probably you have a shared hosting. The shared hosting is a simple concept of sharing one computer with other people in order to reduce the price. Shared hosting has the price advantage and possible performance drawbacks.
If you are unlucky you can fall in one of the following categories:
1. You brought a hosting plan from a greedy hosting company. They are bagging lots of clients on the same machine, the result being easy to anticipate: A slow website, many requests failed,… Sometimes you might get offers to move on a better plan because your scripts occupies “too much of the CPU”. You can contact their support in this case and raise the issue. I’m sure that in this case they already know which are the issues, but they will try to convince you is your fault.
2. Your hosting provider is well intended but you get a bad neighbor either having thousands of websites, either one faulty website consuming lots of resources.
3. You are the bad neighbor. You should optimize your script or you should change the hosting plan to a virtual private server. You’ll help yourself and the others.
Before buying a new hosting you can test it. Most of the hosting providers offer one month of testing before buying a new hosting plan. Even if they don’t you can search for a website hosted with them and check how many sites they are sharing the server with. You can check it using this tool: http://www.domaintools.com/reverse-ip/. Just enter an IP or a domain and it will return the websites sharing the same ip. In most of the shared hosting configurations an ip represents only one server.
You can also create a php file and run the phpinfo() function. You will get an idea about the processor:
