So, this is from my experience running tests.
My 4770k at stock (a xeon with the gpu) scores 750 on cinebench
If I disable hyperthreading (essentially an i5) I get a score of 540 (this is slightly higher than what the i5 would do due to 33% more cache.
No ht and at 4.5ghz I get a score of 664. Equivalent to what an i5 would score at the same speed.
750 vs 664
I would go with the xeon. It is more powerful, you will be using it within warranty, and it will stay more current for longer
Take a look at this http://www.bf4blog.com/battlefield-4-retail-gpu-cpu-ben...
When the cpu is the bottleneck the 4770 (essentially a xeon) preforms 20% better than the i5. You would have to overclock the i5 to around 4.5ghz to get the same...