The
E5-2651 v2 is based on
Ivy Bridge architecture while the
i5-520M is based on
Westmere.
Using the multithread performance as a reference, the E5-2651 v2 gets a score of
415 k points while the i5-520M gets
33.1 k points.
Summarizing, the
E5-2651 v2 is
12.5 times faster than the
i5-520M. To get a proper comparison between both models, take a look to the data shown below.