Looked through the control panel.
You should also be able to see how the server and its services are performing in the CP, and most times our site is slow is when the load is up to about 6 or 7. Above 10 and the dreaded "server busy" error can occur and is usually when another site it doing something server intensive or a spammer has managed to get an account and is... spamming.
My son's site was hacked while I was away and some phishing files upped. A short while after the host suspended the account and deleted the files (including the site's original files). As I am a reseller with them I can rebuild the site at my convenience and lift the suspension so no harm done, but I was glad and impressed to see they were vigilant and intolerant of other accounts abusing the server resources and how quickly they acted.