I have an Acer Aspire S7 ultrabook (see system specs). I recently changed my SSD from the original 128GB in a RAID 0 to a Crucial MX200 500 GB in AHCI mode. I reloaded Windows 8 from recovery disks after changing to AHCI mode in BIOS. I've reloaded a few key Acer programs and updated all drivers. The computer works well and there is no appreciable change in performance in the new AHCI mode.

However, one change I have noticed is that the laptop is slow to go into hibernation when on battery. When connected to AC power it takes about 7 or 8 seconds to hibernate. When on battery power it takes 75 seconds or so. The computer comes out of hibernation to the login screen in less than 5 seconds whether on AC or battery - fast either way.

The laptop used to hibernate in seconds prior to reloading Windows so I know it can be done, I just can't figure out what's causing the delay now. I have made several changes in the power settings to know avail. I disabled the Acer Power Management service with no change. It seems like the computer is waiting for something to timeout but I can't figure out what.

Any suggestions on what to look for that might be causing the delay?