Where are you saving to? Hard drive, local server, remote server?
I know myself, I work with a local storage server onsite and I can save a 10-15GB file to it in about 1-2 minutes. If I have to save to our corporate server, that same file would take about 30-45 minutes to save each time I hit save. Same is true too for adding a file to the render queue, if my Scenes folder is located on that remote server, it takes the full 45 min to save versus having it pointed to my local server or my local HDD.