Both models
i5-3337U and
i3-3120M 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 i5-3337U gets a score of
48.3 k points while the i3-3120M gets
47.8 k points.
Summarizing, the
i5-3337U is
1 times faster than the
i3-3120M . To get a proper comparison between both models, take a look to the data shown below.