From the DSP FAQ:
Note that Roon currently runs the DSP engine on one CPU core per zone–so this reflects the load relative to consuming a full core. “2.0x” means you’re using 50% of one CPU core to play music in this zone.
Currently, I"m playing a local copy of the Mac’s Rumors (24/96) and upsampling to 24/192. I’m getting 32.2x which means, if I am understanding the FAQ correctly, I’m using (100/32.2) = 3.1055 or 3.1% of one of my 8 cores to do the upsampling. Is this correct?
If so, then why not just finish the calculation and display “3% CPU Load” instead of 32.2x