HGST - WD Ultrastar DC HC520 HDD | HUH721212ALE600 | 12TB 7.2K SATA 6Gb/s 256MB Cache 3.5-Inch | ISE 512e | 0F30144 | Helium Data Center Internal Hard Disk Drive

These are good drives, used for storage /backup so rarely run-up but haven’t let me down yet.

Bought this based on its excellent results in the Backblaze reports. Performance is good and great value for 12TB and 7200rpm. One small annoyance: there are more mechanical noises than I expected from a modern HDD (and this drive has passed all SMART and bad sector tests). They are audible through a full tower ATX case (Fractal Design Meshify 2XL) despite being mounted using rubber grommets etc. So you certainly know when it's working, much like a 1990s HDD or 5.25"/3.5" floppy drive. Not a big deal for me but something to be aware of.

This is an enterprise-quality drive --- a big investment in reliability and huge capacity. This is the first drive I've purchased with more than 6-TB (my preferred drives to date have been Western Digital Black 6TB drives). I have to say, I'm largely a convert. One little gotcha -- as a newer drive, and one aimed at the enterprise market, the screw holes for mounting the drive are not the same as the standard ones used on 500-GB to 6-TB drives of years past. Two are the same, and two are different on the sides, and similarly on the back. So while it's plug compatible (as a SATA drive) some mounting brackets are not compatible with it. I have an older Mac tower with four disk slots (mounting brackets not compatible) and an external RAID array enclosure with 4 disk slots (mounting insertion completely compatible). So, buyer beware ... look at the pictures of where the mounting screw holes are, and make sure they match your setup (the change is readily visible ... not a slight misalignment, but some holes missing, some extra threaded holes).

First, I'm going to fault myself. I thought I had did my research on drives before pulling the trigger. i ultimately went with the HGST brand because it was getting good reviews and the helium tech seemed like a good buy in. This would have been my first drive in my NAS that I build. I failed to notice that this has POWER-DISABLED technology. I did not know what it was until i got this delivered. I have not been able to get this to work. For those who don't know, this was introduced a few years back and requires a special motherboard in order to allow the drive to be remotely disabled or rebooted. For us mortals, there is a work around for by disabling the 3rd pin in order to allow the drive to work. I ordered some kapton tape and covered the 3rd pin. When rebooting the PC and going into bios, I am able to see the drive. I then launch into windows 10 and the drive is not found. I go into disk management, still no drive. I reboot back into bios and the drive is no longer listed. I cut power to the machine for a few minutes and boot back up and it's the same cycle. I have just now ordered the molex to sata connector which bypasses the power going to the 3rd pin (which is recommended on the HGST site). Still no luck. It has been almost two weeks and I have not been able to get this to start. Unless you have a need for a drive to be power-disabled, I would steer clear of this drive. Now I'm stuck with a $330 brick unless I can return it. Very, very frustrated.

Worked perfectly for in a freenas setup of 6 disks.