I too am experiencing slow render times but only on one of my computers. I installed the trial of premiere pro on my surface pro 2017 (m3 4gb ram, very underpowered!) and on my slightly old workstation pc (xeon-2660 8 core 2.2ghz, 20gb 1066mhz ram, 256gb ssd, Nvidia Gtx 570).
SO I was expecting my workstation to completely outperform my surface pro but the opposite happened! I tired to render a reverse of a 3 minute 4k mp4 from my mavic pro and after 5 minutes of rendering my surface pro was at 23% where as my workstation was only at 12%!
Whilst I was very impressed with my surface pro I was very disappointed in my workstation. Any thoughts?