Scratch disks act as virtual RAM (albeit, slow RAM) after Photoshop has used real (wired) RAM. Adobe recommends that users set their scratch disk to the largest available internal drive on your system.
After reading Jeff Tranberry’s article, How to tune Photoshop CS6 for peak performance, I decided to change the order in which my scratch disks are utilized. Bad move, because as it turns out, I received the following error dialog:
Photoshop could not open scratch file because disk not available.
In the past, I assumed that I’d have to wipe out all my preferences to revert to my original scratch disk selections. Today, I discovered a much better way…
Read on to learn more…
Holding down Command+Option while launching Photoshop will let you reconfigure your Scratch Disk settings.
There is no need to delete all your Photoshop preferences. I’m still trying to figure out why my revised scratch disk settings yielded the error in the first place, but at least it’s good to know that I can switch scratch disks on the fly if I need to.
As far as why my new scratch disk settings didn’t take, my hunch is that it has something to do with permissions on my other internal drives.
Thoughts? Tips? Share ’em in the comments below!
-Krishna
John
October 15, 2012 at 11:48 amDoes this also work in Lightroom?
Krishna Sadasivam
October 15, 2012 at 10:54 pmI don’t know – I haven’t tried it with Lightroom. Anyone care to comment on whether this tip works with Lightroom as well?
Adam
October 16, 2012 at 8:56 amI had SO much trouble getting scratch disks to work. Photoshop is installed on my C drive which is a fast, but small, SSD, and I wanted the scratch drive to be my big, regular, drive, but permissions meant it couldn’t access it. It took me ages to get it to run as an Administrator. Such a pain.
Krishna M. Sadasivam
May 14, 2013 at 10:40 pmI finally found the solution to the scratch disk error issue. On the Mac, select the HD you want to assign as the designated scratch disk. Get Info (Command-I). Check the “Ignore ownership on this volume” box on the volume that you want to designate for your scratch disk and you should be back in business. This did the trick for me.
Marissa
July 28, 2016 at 5:01 amOMG thank you so much! This worked like a charm. I was so worried I accidentally did something that I was going to regret – like deleted a hard drive or something! Lol Pheww! I just held down Opt + Cmd while I clicked on the Photoshop launch file and it gave me the option to change my scratch disk. It was set to HD2 (Hard Drive 2) so I changed it to Startup because I remember seeing my Illustrator’s scratch disk was Startup. As soon as I changed it to Startup, Photoshop opened right up.
Krishna
July 31, 2016 at 7:21 pmglad to help, Marissa!