The whole identification process is one of Roons most intensive processes. Even when albums are already identified Roon often has full metadata updates where it can and often does use up 100% of its the cpu allocation refreshing metadata. As a result remotes can stop responding to other events and it can affect playback until it’s finished. Many of us have reported this odd behaviour but as of yet nothing has come of it. I have only 9 unidentified albums in my collection so it’s not this, I have a good number of compilation albums but not excessive amounts and only a few large box sets of max 11 discs. So it’s not this either. These metadata updates are seemingly random as there is no pattern or set time and 99% of the time they are when you’re likely not using Roon so for many they are unaffected.
Roon have said or I should say one member of support mentioned in a thread where a user was having major performance issues that a large proportion of his collection was unidentified albums and bootlegs etc and was likely the cause for this users performance issues. It was claimed that Roon will continue to keep trying to identify these albums and with a large number consume a great deal of resources doing so. Not just at these metadata updates I mentioned but at any rescan and likely other times. So it may well have an affect but I am sceptical it’s the whole picture.