Xeon is the server version of Intel's CPUs.
The model of Xeon makes a lot more difference than the brand name.
Xeons mostly match up with the consumer versions of CPUs very closely.
Sandy Bridge versions of i5-2500K / i7-2600K and Xeon E3-1240 / Xeon E3-1270
Main difference between those is the i5-2500K 3.3Ghz $220 has no
hyper-threading w/ 6MB L3 cache and Xeon E3-1240 3.3Ghz $266 has hyper threading w/ 8MB L3 cache. All use socket 1155 motherboards.