Why are you clicking on the folder under Drives & Devices? I assume you mean Drives & Devices>Explorer>Disk or Network>Folder.
That method uses the operating system and looks up the hard drive, so how long it takes is more to do with your hardware than MC. As an example, I have over 28,000 files on a shared drive accessed over a 1Gbps network, and that took about 90 seconds to "refresh" using your method, the first time. The second time, no doubt because stuff was cached, it took less than 20 seconds. The third time it took less than 5 seconds. In Windows Explorer it is quicker, but that is understandable to me; MC is called OS functions, not using its own.
But, if you want to see new audio files in MC immediately, just run Auto-Import and then look at the Audio views. Or, if you have Auto-Import set to run in the background, and the files are on a system that reports file events, just put the new files in a watched folder and check them in about 5 minutes. See
http://wiki.jriver.com/index.php/Auto-Import.
Media Center's Background Auto-Import works by:
## Monitoring File System Events for changes and responding instantly to only those files that changed in a watched directory.
## Running a background full-scan of the defined watched directories, and checking for changes, once every two hours. This is run with a low thread priority to prevent it from impacting foreground tasks.
Also, you can check for recently added music using the "Recently Imported" Smartlists, specifically the "Audio -- Recently Imported -- Imported this week" or "Audio -- Recently Imported -- Imported today".
