Picasa is a great software to view our photos with a great animation. I use windows since I am using my laptop but never liked the default photo viewer that comes with windows.
So I have installed picasa and there will be no lag or what so ever in viewing our pictures. there is a lot of stuff in picasa as well it can edit you pictures and give some effects to give more life into it. create collages of your collections into numerous effects.
The big advantage of picasa is that it automatically collects all your pictures of laptop and kept is its timeline. you can search your gallery by past time as well. install picasa and you will love it for sure. a great replacement for windows photo viewer.