The time varies quite a bit based on:
- Library size
- Hardware performance
- SSD vs spinning disc
- Mac vs PC
- Windows version (newer is consistently better for I/O performance)
Macs are a good deal slower at this kind of thing than PCs. Running the Roon database on a spinning disk makes the process take as much as 5-10x longer. SSDs and flash storage are an enabling technology for products like Roon.
The longest test that I run regularly takes 18 minutes to update a database of 220k tracks on a ~3yr old windows machine (ivy bridge i7, ssd, windows 8.1). The other test that I’ve run a few dozen times, 50k tracks on a ~2yr old macbook pro (i7, ssd), takes about 8mins.
There are some optimization techniques that we can use to speed this process up considerably, but they rely on temporarily using large amounts of RAM during the update. We briefly released a faster version of the process to alpha testers and pulled it back because it was not stable or reliable for people with large collections. Once we have 64 bit builds up and running, we will try turning it back on.