[Michael B]

Probably the problem is you, not the host. If you see the server's ping raising suddenly, it's because your network connection. When you're using many resources from your connection, you will have a lower performance and therefore bigger ping. The response time will increase, as Mr187 said so ping can reach one second.
You can test this phenomenon by checking your SA-MP client before and while brwosing a web page. Ping will raise suddenly to bigger values.