Both models
i7-3687U and
i5-3320M are based on
Ivy Bridge architecture.
"Ivy Bridge is the last Intel microarchitecture for which there is official driver support for Windows XP . It is made under 22 nm Tri-Gate transistor (""3D"") technology and is basically a Sandy Bridge shrink. It has PCI Express 3.0 support and RdRand instruction for security tasks."
Using the multithread performance as a reference, the i7-3687U gets a score of
51 k points while the i5-3320M gets
59.1 k points.
Summarizing, the
i5-3320M is
1.2 times faster than the
i7-3687U . To get a proper comparison between both models, take a look to the data shown below.