Media Encoder render extremely slow

Render speed of Media Encoder (2018) is x4 slower than premiere pro cc 2018 in same File export with same rendering settings.

Rendering time of the file (4K video. H.264 Mp4.  2 min. length) :  Premiere Pro - 9 min, 

                                                                                                          Media encoder - 41 min

My System:  AMD Ryzen Threadripper x1950 (16-core)

                     GeForce GTX 1070

                     64G RAM of DDR4

                     2 x 256G SSD