PSU is not a bag of potatoes. It is called a power rating. E5-2697v2 = 130WFirePro W7000 = 150W(absolute max) x2=3002x Toshiba X300 4TB = 2x7W =14WΣ444W x150% overhead = 666W PSU is needed.   You have enough.  
Hey all, I recently picked up a Dell Precision T3610 and wanted to verify if I should upgrade the 685w PSU to one with a greater capacity. I intend to install the following:   I see that there are 845w and 1300w options available for newer Precisions in that family but am unsure if I need the higher capacity. Additionally, other threads/forums have suggested that the higher capacity PSUs don’t physically fit into the slot for the T3610. Thank you for your time and support.
Dell Precision T3610 - PSU Capacity Inquiry