Both models
G3900TE and
i5-6400 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 G3900TE gets a score of
49.3 k points while the i5-6400 gets
129.5 k points.
Summarizing, the
i5-6400 is
2.6 times faster than the
G3900TE. To get a proper comparison between both models, take a look to the data shown below.