Problem: System goes into weird sleep wake states - inconsistent external drive mounts and kernel panics. 1) System will often not stay asleep - wakes after 1 second sleep 2) If System sleeping, will reboot at night (Kernel panic) - with sleep wake crash - reports problem to Apple in the morning. 3) System will not wake up, hung and needs hard power off 4) Pegasus R4 disappears - won't remount till powered off/on Anyone else have these issues or anyone have Mavericks with TB drives working - especially Thunderbolt 2? Could be TB2 issues as other posts seem to have that as common denominator. My config: Mac Pro 2013, 6 Core / 64GB / 1TB SSD / D500 Two NEC 27" - Mini DP connect to MacPro directly 1 Pegasus R4 Thunderbolt V1 - 8 TB Raid 0 (4x2TB) - latest firmware 1 Areca 8050 Thunderbolt 21TB Raid 5 (8x3TB) - latest firmware 1 Anker USB 3.0 9-Port Hub with 5V 2.1A Charging Port hub VL812-B2 Chipset and updated Firmware 908 All Apple Thunderbolt cables attached to Mac Pro - not chained from other TB drives Mavericks 10.9.1 - created from clean install All software/firmware updates installed Same problem as http://www.xlr8yourmac.com/archives/jan14/012414.html Thunderbolt external drives worked fine on Mavericks 10.9 on Mac Book Pro 2011 17" - no sleep wake problems. Pegasus support suggested turning off power management on R4 - but no effect on Mac Pro issues. The Pegasus R4 ran flawlessly on my Mac Book Pro - including sleep / wake. Turning all power saving features off helps, including wake for network. I have to power down at night now. Other users have reported TB problems with hardware other than Mac Pro 2013. Seem to point finger at Mavericks. Will post update once I test various Sleep settings.