Please let me know the Intel® Xeon® processor E5 that you have in mind so I can compare the features of that processor with the Intel Core i7-3960X.
You can also go to this link to compare a group of processors:
For pricing and availability information you can contact any of our Authorized Intel® Distributor, also they will be able to provide you further processor recommendations according to your personal needs.
You can find a list of Authorized Intel® Distributors at:
Please check this comparison chart:
The Intel® Xeon® processor E5-2670 has a slower clock speed, but it has more cores and higher cache RAM, also it has faster system bus, so the performance in a multi-tasking environment will be better than the Intel® Core i7-3960X processor.
Please make sure that the software that you will be running is designed for multi-tasking environment, so the software is capable of taking full advantage of the all the cores of the processor.