On March 3, 2015 I finally got my Mac Pro late 2013 to sleep/wake reliably – more than 1.25 years after Apple released it.
The latest version of the Apple Thunderbolt firmware is required, Yosemite 10.10.2, and Areca 8050 Firmware & Boot Rom V1.52 2014-12-26.
As well I need the latest version of Promise Pegasus R4 Firmware: 5.04.0000.36 otherwise it reported that the disk was not ejected when waking up.
Here is a screen shot of my current Energy Saver settings:
