So I've been working on a movie poster and, naturally, I started the document at 27" x 40" at 300dpi since this is standard. After working with the document for some time, it became painfully slow doing anything even with basic functions such as clicking on a layer or moving the mouse. The same thing is repeated even after restarting the program, the document and the computer.
I looked into it a bit online and found some useful information like making sure of the scratch disk settings and cache levels and such were set properly, but even with everything fully optimized and about 800GB of free space for scratch disk and a designated 89% of 16GB of RAM, I'm still experiencing the same slowdowns.
I then looked into the resolution for posters... or tried, to which the results fluttered from 12dpi to 300dpi to being dependent strictly on whatever print machine you're using. Is there a standard resolution for movie posters or is it truly dependent on wherever I go to get the posters printed?