It is easy to assume that a dedicated server host will provide you with the latest hardware, but the only real way to make sure of this is to evaluate the hardware specs they provide. Many new server administrators pay close attention to operating systems, control panels, and software, but neglect one of the most important components of a good server: the CPU.
While some server web hosting companies offer the latest server processors on the market, this is not a guarantee. For example, I have seen some companies offer lower-cost servers with Celeron processors. These servers are less expensive for a reason. The Celeron processor is designed to be a desktop CPU and is not even suitable for higher-end desktops, let alone servers. Although the CPU may have the same clock speed as a comparable Core Duo processor, it generally has less on-chip cache and will not perform at the same level.
There are, on the other hand, processors that are catered to servers, such as the Intel Xeon family and the AMD Opteron. Both are 64-bit high-performance chips that run well in servers. If there is some extra cost involved, it is most likely worth it, especially if you want your server to be scalable.
Another aspect your CPU decision to consider is whether to get a single core, dual core, quad core, or higher. Multiple core processors are able to multitask better. That means more things can happen at once. On a web server, which may run several instances of identical processes, this is ideal. Depending on your anticipated load and scalability needs, the more cores, the better. There is evidence that have two dual core processors is better and faster than having a single quad core, and there is also evidence to the contrary. Results may vary, and you should check the research before reaching a decision.