In the event that you host your sites on a dedicated server, you would expect that they will perform ultra fast and that the access speed to them shall depend exclusively on the Internet connection of the visitors. Having said that, this will not be the case if the server has lousy network connectivity or employs a network card, which just cannot cope with high volume of site traffic. If this is the situation, it'll take quite a long time for your sites to load if a lot of people open them at the same time or visitors may see error messages. Because of this you may lose visitors as most likely many people will not return to your site in case they have experienced difficulties or slow loading speeds. That is why you need to pay attention to the network components of any new hosting server which you get and not only to the main hardware such as CPU, Ram memory or hard disk.