Does the WD Ultrastar DC HC550 (18 TB, 3.5", CMR) also click every 5 seconds when it is booted up?
It sounds like a drop of water dripping onto the bottom of an upturned plastic bucket.
You can still hear the clacking at a distance of 6 metres. I have tried them in 2 external housings. If you touch the external case, you can even feel the clack. When writing data, the read head noise can also be heard, but it is within the normal range as with other disks and much quieter than the "clack every 5 seconds" that also occurs during data writing in addition to the read head noise. It works, but a mechanical noise whose vibration can still be felt on the external housing sounds like a defect to me. When it is not in use, the clacking stops at some point (presumably hibernation), but as soon as I start reading or writing again and it starts up again (with a very loud rattle of about 3 seconds), the clacking every 5 seconds is also back.
Beim beschriebenen Phänomen handelt es sich gemäss Auskunft von WD um ein Feature mit Namen «Preventive Wear Leveling»:
«The 'noise' heard is due to a feature used to prevent disturbances in media lube due to prolonged dwelling at a single location. This is common for HDD suppliers as a preventive activity for reliability. Normal operation typically forces seek away and the seek noises heard are expected. During moments of idle, there is less activity and the unexpected sound is more noticeable (Approximately every 5 seconds). Directly attaching the drive to a metal chassis can amplify this occurrence to make the hard drive more audible.
On many older models, this would happen maybe once a minute. But on some builds it’s maybe every 5 seconds.»
Dazu gibt es auch ein schönes Video:
https://www.youtube.com/watch
