I had similar (older) 3U supermicro 16bay chassis and each power supply will use about 13-17W and backplane about 5W (Mine was JBOD, not expander ). So about 35-40W
This is without fans. Each middle fan (full speed is about 1A * 12V = 12W. x 3 = 36W) Back fans are 0.55A at 12V will be 6W x 2 = 12W.
I've wired mine at 5V instead of 12V and put them at PWM and they are using about 6-10W together.
Also I've replaced Power Supplies with Platinum and now each are using just 10W.
So my current power draw is
10W for PS (I only connected one PS, instead of 2), 5W backplane + 10W for fans
So about 25W together, instead of about 80W originally.
All this without motherboard and and drives.
-Stan
Ok, question on these..how much power will it draw just doing nothing? I understand it doesnt include anything related to the actual server and its just the Power Supply, back planes, fans, etc. The dual 1200watts power supplies just freaks me out thinking it will drain a lot of power by itself while idling most of the time even if I spin down the drives.
Thanks for responding..I'm new to building servers.
-Jim