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

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 well since : "Last purchased Feb 17, 2020." Now it's dead. It served me well, but I had hoped to get longer life from it. Regardless, too many other negative reviews and those saying that they received "used" drives. As a resulte, I'll pass on this brand for its replacement.

You might be asking yourself. There are several reviewers complaining that they could not get the drive to spin up due to an enterprise feature that leaves the drive off until it’s enclosure allows it to spin up. I didn’t have any trouble with it in my QNAP NAS — though I wouldn’t use it in a desktop. It spun up immediately and began rebuilding my array. I’m replacing 8TB WD Gold disks, bought a couple years ago, to increase my capacity. These disks are physically identical to my old ones. Seeing that definitely inspires confidence. Another reviewer complaint is that there is no warranty on these disks. That’s not true, these reviewers are not familiar with how hardware built for enterprise use are typically warranted. The manufacturer does provide the replacement disks, but not directly to the purchaser. They must be purchased from an authorized reseller, and reseller transacts the warranty replacement. If you buy these and the warranty is important to you, you should check whether the seller is authorized by WD or not before buying. These disks are being sold rather cheaply by some sellers for what they are. I’d guess that many of them are not authorized resellers and are basically selling them cheap because you are forfeiting the warranty option by buying from them.

Drives are great, got 2 12TB, works fine out of the box, works great in my Synology DS215J NAS replacing my WD Red 3TB drives. The drives are noisier than the WD Red, I can hear the heads seeking during activity, not squealing or bearing, just head movement light "knocking" noises. Not the end of the world, but the old WD Red were totally silent; I couldn't hear anything from them, so I was a bit surprised these were so noisy. Warranty is a bit sketchy. The listing did note: "Up to 2.5M hours MTBF with a 5 year limited OEM warrant direct with Authorized Reseller" I registered the drives with WD and they said the warranty was until Dec 2024 (so just less than 1 year) since the drives are sold OEM it's up to the seller to provide the warranty. We will see if the reseller "The Nekid Cow" will provide warranty service in the next 5 years if I have an issue with the drives. I would have felt more comfortable if I had the 5 year warranty with WD, but I do realize I was getting a good deal on these drives so is reasonable. They were new in boxes, good condition. I ran a full SMART test on them and all was good so I think things should be fine. I'll update the review later if there are issues.

Bought a Western Digital 12TB DC HC520 HDD listed as new. Arrived in a very plain unmarked box no labels of anything that would hint of what was inside. Did find inside what I thought was a new 12TB HDD until I looked at the manufacturers date of Oct 29-2019. Something nearly 5 years old is NOT new. Gave it a try hoping it would still work. No luck in a new computer. Would not boot up. Was not even recognized as installed. I have now tried two with the exact same manufacturer date and exact same result would not boot up would not even try. I have asked for a refund and Amazon needs to think about it…. for up to a week. I got scammed and Amazon needs to think about it!!

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.

Worked perfectly for in a freenas setup of 6 disks.