Just a quick tip if you have ever run into the file size limit of 2 GB when trying to save a PSD file in Photoshop: Change the format to PSB, which is the Photoshop large file format. PSB actually stands for “PhotoShop Big” and has a theoretical limit of 4 ExaBytes. That’s 4 billion GB (yes, with a B, not that it make any difference in practice whether it’s million or billion). Thus, given the PSB limit, you’ll first run into other size limits: one imposed by the file system on your computer, another by the max PSB width/height of 300,000px, and the last one by the size of your hard drive. 😉
Most people will most likely never experience that issue, but it might happen if you work with really huge stitched panoramas or files with a lot of layers, smart objects and filters.
Hope that helps!