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

Bought this when it was at a low price. knowing It not a brand new drive thought I take a chance and I am glad I did. Was originally going to buy a new 5tb external to back up a 3tb internal. Decided to buy this instead and swapped it with my 3tb and transfered data with a external usb sata dock I already owned. at first its seemed like was not working because it took a while to show up on my pc after acouple of restarts and checking on my bios saw it was working fine and inis formated it. after a month it still working ok ocassionally can hear it spinning up but it not that loud really.

I bought these drives from Amazon US to be shipped to the UK. TLDR don't buy these drives whether you're in America or international. For testing, I used HardDiskSentinel. Write and read testing checks sector by sector for speed and whether they're good or bad and short self test. I usually do a long/extended self test as well but didn't get a chance to with these drives. With these I decided to do the short self test first and they were all loud. I've done this test a lot and never had a "renewed" drive make such a loud noise or even new HDDs with all of them pausing here and there which again was a first. I then ran the write and read test and on all 4 drives within a few hours thousands of bad sectors popped up and due to the sheer amount of them, the test was stopped by HardDiskSentinel. Smart status was still 100% even after the discovery of those bad sectors. Never trust SMART status to tell you what you need to know, due diligence is always required, especially with "renewed" drives. Each drive had the total on time and spin ups and downs still in the SMART data and along with the horrible sounding read heads, these drives were not renewed, not refurbished. They were wiped of data and that's about it in my opinion unless they missed all these issues which are basic and sorting them is usually apart of renewing a drive. Whether all 4 of these drives were one offs? Unknown but I won't ever be buying them again. Spin up and down on 2 of the drives were about 50-60 which is to be expected but the other 2 had over 1000 spin up and down which was a tad unusual for enterprise classed drives. All 4 of them had over 29,000 hours of on time. Very disappointed in what was meant to be renewed drives but this is either a huge mistake and they packaged the wrong drives or these drives have been advertised as renewed fraudulently. Had some very high hopes after waiting 12 days for them to finally get shipped and then another 5 days before they got to my home to find out they were duds and so continues my fight with Amazon to get a refund so I can buy some more drives and hopefully get something functional this time.

Purchased 3 of these for my QNAP NAS, where they sit in RAID5. All of them about 4 years (plus/minus few months) of use, only few power cycles, 100% OK SMART, no bad sectors etc. No need to cover any pins in my QNAP - they work straight away. I wasn't able to enable hardware encryption (SED), as even though it's been turned off (drives are not encrypted), it's not been reset to factory settings, so I don't have a hardware key to re-enable it from scratch. That functionality is lost, then. Also, these drives are relatively loud, though also are fast - something for something. After 2 months one of the drives just randomly died (no warnings in SMART, no bad sectors, all was great and then suddenly started the click of death and that was it). Sent it back to Amazon and got a refund, then purchased another one as a replacement - we'll see how that one is doing when it arrives.

This renewed HGST WD Ultrastar DC HC520 12TB drive has been a solid choice for my home server. It runs quietly during idle times—which is most of the day—and while it does get slightly louder under heavy load, the noise level is still acceptable. So far, its performance has been reliably smooth and exactly what I needed.

good value

Arrived pretty quickly from America despite Christmas holidays. All tests show 100% health. Working well in home server.

Drive started operating very slow with latency over 4000ms even for smallest data read / write operation. Drive is defragment on a weekly schedule and chkdsk never gets completed as drive goes in high latency. Very disappointed as it did not even last a year.