I just opened Photoshop to do a simple adjustemt to an illustration. First, the program has a ridiculous problem with its performance!... I have a iMac 27" 5k with 8 GB of RAM... and by just scaling a drawing, the program takes almost 3 minutes to do so!... On the other hand, I adjust the size of the board in CM but everytime, the program would adjust the size in Pixels and with another number (e.g. instead of adjusting the art in 37cm x 150cm, it would do something like 230cm x 500cm)... I supposed this is an issue with the last update! Because before that it was working totally fine!... Please, do something about it!!! I also had to put the performance option of the program and the RAM to its maximum, and still takes time to do a simple scale task!... Absurd!!!!!
Never, ever, set RAM usage to max! Other programs and processes need memory too, and this is a certain way to bring the whole system to its knees. Always leave a couple of GB for other processes. 5 GB for Photoshop should be about right here.
Your installed RAM is certainly on the low side, but it should still work as long as you have sufficient scratch disk space. There is never enough RAM anyway, so Photoshop depends on writing temporary working data to disk - aka the scratch disk. If this is a fast disk with enough free space, everything should move along with minimum performance impact.
From your description, it sounds like scratch disk is the problem here. You need to have at least 100 GB, but 500 is more comfortable.
My iMac still has more than 80% free of space in disk... I have 2TB and disposing of 1,73TB Clearly its not an issue of the disk.
Thanks for the response but this doesn't help me, mainly because last week I was working on bigger files like complex mockups and other of the same kind. These I just opened again and they work fine! I guess the main issue is with the original file I was working with today from the beginning.