Turning Off Safe Sleep
Open the Terminal (in Applications > Utilities), then type the following command:
sudo pmset -a hibernatemode 0
Press Enter. You’ll be prompted to enter your password. Do so, then press Enter again.
Next, type this command:
sudo rm /var/vm/sleepimage
If you decide to re-enable Safe Sleep, just replace the first Terminal command with this one:
sudo pmset -a hibernatemode 3
Changing the “0” to a “3” turns Safe Sleep back on, where data is saved during Sleep to both the RAM and the disk/SSD. Reboot after the change.
Disabling Safe Sleep doesn’t mean that you can’t put your Mac to sleep; closing the lid still puts it in a low-power state. It just means that if you lose all battery power while sleeping, you’ll lose your active data.