Why is a temporary photoshop file weighing 30-40 GB?

Question

Adobe Photoshop

RAM 4 GB, photoshop given 2 GB.
The weight of the layout is rather big - 205mb, but still:
Why does a temporary Photoshop file weigh 30-40 GB?
The file is created immediately when the layout is opened.

Answer 1

This file contains the entire history of actions, all used color profiles, all the contents of all layers and objects in uncompressed form (in fact, compare the sizes of RAW and JPEG eights, you will understand roughly), most likely channel by channel, various other backup information with all sorts of useful things, there caches are written to perform various actions. Naturally, all this takes up a lot of space, but it saves a lot of time during processing and cleans up the RAM. It is recommended to allocate one partition on each physical hard drive / solid state drive as a scratch disk, then you will have a more compact file on each hard drive, but most importantly, the load will be distributed across different hard drives with more efficient use of the bus. But using several partitions on one hard drive makes little sense.