Old photo library won't import

Background: took my 2010 iMac and added a 256 ssd next to the 1tb hd. My wife has hundreds of gigs of photos so I have her library on the hdd and selected it to the main library when you open iphoto. As it began the process of opening it takes forever. The first time it failed at 30% then I let it run again for two days and it never passed 30%.

Any help would be great.

This forum is horrible typing on an iphone.