How to view image in multiple sizes at once in CS6

Is there a way to view your current doccument in multiple sizes at once in CS6, similar to Subwindows in Krita? I want to be able to zoom into my current project to work on details, but still have another window that shows the live view of my project at 100% so that I know what the changes I'm making look like "at size" without zooming out to look and then zooming back in to continue my work.