It uses the CPU for audio transcoding, but its not really a performance hit. I used to have a dual core Pentium Gold and had no issue with audio transcoding on the CPU… But it is worth getting more cores/threads and better performance for some of the other things that rely on the CPU - especially since some of those tasks utilize only a single thread.
Things like subtitle burn in, deinterlacing, and background thumbnail generation.
Here’s another thread where I showed CPU stats during transcode of 10 streams. In this case, the audio was transcoding from English (DTS-HD MA 5.1) to AAC on the CPU for each stream, and as you can see it didn’t kill the CPU:
I don’t really think you would need more than an i3 or i5 unless you want to transcode a bunch (5-10 or more) streams simultaneously?
