Both models
i3-6006U and
3855U are based on
Skylake architecture.
Sky Lake is also known as 6th generation Core. Include Thunderbolt 3.0, SATA Express and Iris Pro graphics with DirectX 12. It uses LGA 1151 socket for mainstream models and LGA 2066 for X-Series. Sky Lake comes with AVX2 support in all mainstreams CPUs and AVX-512 in some high end models.
Using the multithread performance as a reference, the i3-6006U gets a score of
47.5 k points while the 3855U gets
24.6 k points.
Summarizing, the
i3-6006U is
1.9 times faster than the
3855U. To get a proper comparison between both models, take a look to the data shown below.