iPhoto Rebuild Library

[onlymiah]

I keep syncing my iPhone with iPhoto and every time I close iPhoto my last sync seemingly disappears (everything still appears in the iPhoto Library "Masters" file). I read a tip to hold down option and command when I click on iPhoto and choose rebuilt library to fix the problem. Is it normal to take a LONG time to do this? I chose option one and left it on for most of the day and it sat at 74% FOREVER. Finally I closed it and retried it with option 2 and it is still taking a long time. I have a shade over 20,000 photos in my library. It bugs me because it is keeping my CPU temp right around 200°.