I do not have an answer for you but I am experiencing much the same issue on my Mac, so much so that I now cannot use PS CC 2018 for more than 5 or 10 minutes before my Mac grinds to a halt. This is a really irritating issue and something that Adobe needs to sort out sooner rather than later. I hope that somebody with a lot more knowledge of these things than I can shed some light on why this is happenng, in the meantime, frustration reigns...!.
It sounds as if it is using a lot of scratch space. What are your scratch disk settings?
My scratch disk is set to my Mac HD only, should I make my external HD active only and not the Mac at all then?
If there is enough space on the external HD, this may well make things better. There could be a fault in Photoshop, or something you are doing that makes Photoshop think it needs to work with an enormous pixel size, but this at least could help the process finish.
OK, I'll swop it over and see how it goes from here. Many thanks for your time and advice.
I have been using Photoshop for over 20 years and have a very annoying bug with Photoshop CC 2018 - I have a 500 gig solid state drive that I meticulously maintain and I guard against filling it past a certain point - I always have 200 gig free for scratch disk use or for temporary use in moving files around. Recently, after I quit photoshop (I work in 2400 dpi as I am a cartoonist and illustrator, so my file sizes are gigantic, multi-gigabyte usually), the scratch disk from Photoshop does NOT REVERT to visible storage space, instead, my hard drive shows a false number that is respected by the OS, which means that even after I reboot multiple times and clean my caches using Cocktail, the scratch disk usage remains.... Purging all makes no difference...
Sometimes the scratch disk space goes away in like half an hour or so. I would love to know a Terminal command to remove the scratch disk file ASAP....
This happened to me a couple of times on Windows (CC2017). It wasn't using the entire drive but was using a hell of a lot all of a sudden. When I went to my scratch disk there was a huge PS temp. file there even though Photoshop wasn't running. When I deleted it got rid of the problem.
can you expand on why you need 2400dpi as that is extraordinarily large for most purposes.
Rule of thumb: if your files are more than 10 000 pixels long side, you should think long and hard about why exactly you need that. If you can't come up with a good answer, you don't.
I was curious about what the 2400dpi was for too so consulted Lord Google and since they said they were a cartoonist & illustrator...
For images printed on good quality paper using an offset press, the general rule is that the image resolution needs to be twice the screen ruling used to print the job. Magazines are typically printed using a 150 or 175 lpi screen ruling. This means images need to be 300 dpi. My bird picture is 3000 pixels wide, which means that for the best quality it can be printed up to 3000/300=10 inch wide.
Please note that a slightly lower resolution such as 220 to 250 dpi is also perfectly acceptable for most people. For high-quality jobs such as art books or for images containing critical patterns such as brick walls or clothing with a pattern in it, a higher resolution is sometimes recommended by the printer. Typically 400 dpi is used for such images.
The above rule applies to both color and grayscale images. The notable exception is line art, pure black and white drawings that contain straight or curved lines. Cartoons or logos are examples of line art. Such images need to have a much higher resolution. Most printers recommend 800 dpi as the bare minimum. Preferably resolutions of 1200 to 2400 dpi are used."
Every day's a schoolday
HothWampa for the WIN.
"The above rule applies to both color and grayscale images. The notable exception is line art, pure black and white drawings that contain straight or curved lines. Cartoons or logos are examples of line art. Such images need to have a much higher resolution. Most printers recommend 800 dpi as the bare minimum. Preferably resolutions of 1200 to 2400 dpi are used."
You are the only one who wasn't confident in his/her knowledge and understanding. Yeah, I have been using Photoshop since the beta. I am still learning stuff, but basic stuff like line art resolution isn't one of them...
Anyway. Problem STILL exists. It is maddening.