What's the Largest File Size that Photoshop CS 5.1 can Handle?

Question

I'm building a large landscape montage using about 50 RAW images at 16Mb per image. I've successfully managed processing montages before that were 1.5 Gb but over the course of the few hours it took my rig to process them, they pretty nearly melted my core. Besides the normal stuff that allows PS to run (setting cache and scratch disk size), is there something else I should be doing to run huge files efficiently? Like... Should I skip working with uncompressed TIFFs and save straight to JPEGs? When building intermediate sections, should I flatten my image to reduce file size? I really like the flexibility of post processing an uncompressed image when doing final editing, but I don't want to wait for several hours only to discover that Photoshop has locked up my machine.

Answer 1

Here you can see the maximum size of different file formats in Photoshop

PSD files: 2 GB

TIFF files: 4 GB

PSB files: 4 exabytes (4096 petabytes or 4 million terabytes)

PDF files: 10 GB (pages are limited to a maximum size of 200 inches)

Also per same document the maximum dimensions (in pixels) are:

Photoshop supports a maximum file size of 300,000 x 300,000 pixels, except for PDF files, which are limited to 30,000 x 30,000 pixels and 200 x 200 inches