The fan and hard drives sound are easily heard in a quiet room. The low whirr from the rear 92mm fan is the loudest part on this NAS. With the NAS turned off we found the ambient room noise to be 31.9dB. With the NAS turned on sitting at idle the noise level next to it jumped up to 37.4dB. If you plan on using one of these in a home office or some place that you want low-noise levels, then plan on upgrading the 3-pin 92mm rear fan. It is a simple upgrade that can be done for under $15 and just a few minutes of time.
The NAS came diskless and was equipped for testing with five Western Digitial Red 3 TB WD30EFRX hard drives. Power consumption at the wall for the whole NAS measured between 39-43 Watts when drives were spun up and ready for use.