Haswell i7 o/c or Haswell Xeon dual

I suppose it's primarily for running Pro/E? To my knowledge, only the Assembly module can use more than one core. Last time I checked, part regeneration was all done in a single thread, so you didn't get any improvements by having dozens available. In fact I think the nature of the task may mean it's limited to one thread for the foressable future.

When I looked into all this stuff, I decided the Xeons weren't worth the extra money for this sort of work. I did a thorough comparison between the a first gen Nehalem i7s and similarly priced Nehalem Xeon and I found the i7 performed slightly better. I seem to remember concluding that it was because the Xeon required error-correcting memory, which is inheriently slower than regular non-spacestaion memory. It's also relatively expensive. I found it a little amusing that many workstation manufacturers would push Xeons and low-end "Fire Pro" or "Quadro" over the almost identical "domestic" i7s and gaming graphics cards. I even had a guy from Dell tell me that I could add extra Xeon processors in the future via expansion cards. Yes really.

So far as graphics go, I can't tell the difference between a mid-range pro card and a high-end gaming card (both ATi/AMD). They benchmark very differently, but when I can't see the difference in Pro/E I'm inclined to think that doesn't matter.

This is all a good few years old, so I'd recommend heading over to Guru3D and asking there. It used to be a very good forum for this sort of stuff.