When does PSP2020 write to memory, and when to hard drive?

[boblite]

In the Dell laptop I am now using, I installed a 500GB solid state hard drive and 16GB of memory. I want to minimize writes to my hard drive since I recently saw information indicating that solid state drives wear out much faster than regular hard drives if subjected to a lot of writes. This leads me to ask whether PSP2020 -- if given 16GB of memory -- does most of its processing in memory, and writes to my SSD hard drive only when the edited image is saved by the user. Also, does the the program save a small file to hard drive with each change made to the image, or are these intermediate files written to memory?

It occurs to me that I might save the SSD a lot of work if I keep images on an external USB 3.0 hard drive, though this presumably will slow operations.

[jorgensen]

Process Monitor from SysInternals can tell you that.
At least change the TEMP environment to another drive or Ramdisk if you want to minimize SSD writes.