The #1 Optimization for Photoshop Users: Speed up Save/Open by up to 20X
Want to configure or optimize for Photoshop or Lightroom or video? MPG consulting.
Saving files can be up to twenty (20) times faster in Photoshop, but I find that few consulting clients of mine are aware of it.
The Photoshop skips the compression step, which is a slow single CPU core operation.
checkbox in Photoshop preferences means thatThe amount of speedup depends on how fast the drive is—that’s why saving and opening on a single hard drive will be much slower than on a fast SSD.

Disable compression of PSD and PSB files for up to 20X faster saves and opens in Photoshop CC 2015