1.3 - why is Processing Speed sometimes not displayed with Sonos?

I notice that the Processing Speed information is not shown sometimes in the signal path modal when playing through Sonos. As far as I can tell, Processing Speed is only shown when some sort of DSP is being performed. Is this correct? For example, when playing redbook PCM to my Sonos devices, I do not see Processing Speed presumably because there is no conversion required. However, If I play high res PCM, Processing Speed is displayed as the high res file needs to be converted to a non high res format to a format (44.1 or 48) that Sonos can handle.

However, outputting to any other device, I always see Processing Speed whether or not any DSP is applied at all. For example, with all DSP turned off and outputting to HQP Processing Speed is shown.

Thank you for the clarification.