This depends on the video editing software. And it depends on the drives. I can get either CPU selection the edge by boosting it with better hard disk systems or changing software on one but not the other.
I'm guessing the Xeon is a newer system than the older C2Q Q9550 so the newer chipset should give it the edge as well.
In the end, the benchmark matters.
PS. Yes I have had both types in the past and still have 2 C2Q systems in the office.
Which one of these would be better to build around for HD video editing? Don't try to sell me on something else, just what you know about it