Hey WTHX,
your specs are really good, so it won't be because of that
But that "scratch disk" error does sound related. When looking into
Scratch Disk errors in Photoshop it seems this occurs when there's no RAM available and Photoshop attempts to use your disk as replacement, but that disk is full too.
Having that error means there's not enough RAM available to perform the requested operations (editor and photoshop).
So, a few possible helpers:
1) Free up disk space
2) Check your Task Manager to see the CPU and RAM usage %. If this is very high, you might want to close some applications.
Sincerely,
Kevin