Rekordbox slow analyzing collection

I am new to Rekordbox. My collection is very large. It's 1.8 TB on an external HD. Rekordbox runs so slow if I have my external HD plugged in that it's virtually unusable for performance. Support says that it is because it is still analyzing files. Just to be thorough I completely removed and reinstalled the software and switched to a brand new HD. The problem was the same. I have selected my entire collection and told Rekordbox to analyze the tracks It has been running 25/7 for several days and is not even a 4th of the way done analyzing. Any tips? It doesn't seem it should take this long.