Consider reliability. For example, if an architect or a graphic designer loses a day’s work through a hardware failure, the cost would be considerable. Whenever you’re using a lot of memory, the chances of failure are higher. One of the key features a Xeon processor has over a Core i7 is ECC (Error-Correcting Code) memory. ECC memory enables better data integrity and system reliability through the correction of memory bit failures.
There is a larger range of Xeon processors than Core desktop processors. Xeon processors have up to 18 cores (some with hyperthreading) and up to 45MB of last level cache. Not all Xeons are supported by specific Xeon workstation board and system designs. If you are building your own workstation, it is advisable to check the manufacturers tested and supported list.