Hello.
I am trying to batch transcode about 20 clips to Losless Matroska. My problem is it is only using one CPU core and taking forever! I have a xenon processor with 4 cores with hyperthreading to simulate 8 cores. My default rendering is done with 8 encoder threads and I can see all 8* cores activated. Does anyone know how I can activate all 8* cores with transcoding?
Thanks!

When you select Render, enter a value > 1 in the 'Encode Thread" text box. This controls the number of threads (and hence core usage) when rendering.
I usually enter 4, but try various values to see guage the performance.