I use S3 for my front-end, however my server stays on 24/7. All of the hard drives spin-down when not in use for ~20 minutes, and the OS is on an SSD. I measured the total consumption with the ~9 drives spun down and it’s around 50-60W. My backup machine sits off all week until midnight on Fridays when the server turns it on with a wake-on-lan packet, does the back-up, then shuts it off again.
ET
