We've offer servers either based on i7 or Xeon processors. In this article I will outline why the Xeon dedicated servers are more expencive than those based on i7.
The current line of Xeons are based on the same architecture as the i7. The difference is usually that the Xeons are the cream of the crop. They run cooler and at lower voltages and are spec'd for 24/7 continuous usage. Otherwise, performance is usually identical. Xeons are able to be used in multi-socket motherboards, where i7s are not.
Xeons are also usually the first to be updated. The additional reliability of the Xeons is very important in servers, especially rackmount and blade-enclosed servers (like those we are selling in the UK and Greece) where the lower heat dissipation and power consumption are essential. These benefits usually don't mean too much to all but the most extreme overclockers though, so people in the desktop segment usually ignore it due to the enormous difference in the price of both the CPU and the motherboards needed to support them.
The pipelines are the same, however the Xeons also tend to have more cache and more registers. This along with dual socket capablity is why they are used in high end workstations and also in our servers. More registers is very important with large numeric datasets.Another difference between Xeon and i7 is that the Xeon supports ECC memory, the i7 does not.
Also, some Xeons are designed to work in multi-CPU systems, whereas absolutely no i7 models do. As such, if you want a multi-CPU system, you must use nothing less than a Xeon.