Can you check Windows event viewer to see if there's a crash report for Photoshop
There is nothing in my crash logs in the Photoshop folder, as for event viewer, the only erros that I have that are occuring at arround the same time appear to be a disk error: "The driver detected a controller error on \Device\Harddisk5\DR10"
I have this problem too. Photoshop has become unusable.
I have had these issues since I got a brand new iMac last summer and re-downloaded LR and PS. I will put 4 photos into PS to edit. I can usually do the first four with no issues. I save and close them and return to LR. I select the next 4 photos and open them in PS. Then the lags begin. Particularly when using the healing brush tool. Sometimes the only way to get PS unfrozen is to click outside of the photo. Then undo the streak it just made on the photo and it is good to go, for another minute or so. Saving photos back to LR at this point take well over 15 seconds per photo.
I've assumed it was an iMac problem but from surfing these forums it is an Adobe issue?
Note I did not have these issues on my 2011 iMac. However, I had not updated LR or PS in sometime on that one.