Performance

You are not sharing the system resources such as processor power, memory and disk space with other sites on the same server.

Greater Reliability

You do not run the risk of the server being slowed down, swamped with traffic, or crashed by another site on a shared server.

Security

As nobody else has access to the server you can be sure of having a much greater degree of security and you have the authority to install additional security software on your dedicated server.

Custom Configuration

On shared hosting, you are not allow (in most instances) to install any special software or configuration that your script needs. In most instances, dedicated server will be your only options.

Custom Firewall

Run your own custom firewall to enforce your own access control policy.

Your own IP address

Most shared hosting sites share a single IP address, with site traffic directed by the server examining `host headers'. In contrast your dedicated server has its own unique IP address. On shared hosting, you will be sharing the same outgoing IP address as 200 or more websites and if one of these domains causes the server outgoing IP to be blacklisted, you will be penalized too.

Upgrade Path

With your own dedicated server, you can add more memory, disk space or extra processors as the need arises.

SLAs

A Service Level Agreement and often 99.95% or more network uptime guarantee