HGST - WD Ultrastar DC HC520 HDD | HUH721212ALE601 | 12TB 7200RPM SATA 6Gb/s 256MB Cache 3.5-Inch | ISE 512e | Helium Data Center Internal Hard Disk Drive (Renewed)

I am writing without the help of ChatGPT (I know, weird concept, huh?) so this is totally authentic. I bought 4x of these for a used Western Digital PR4100 NAS I bought off of ebay (Western Digital nix'd the product; they don't sell them new anymore - but it as an excellent NAS compared to others). At first, all drives joined the set just fine - no SMART data issues to report, not a peep for a day or so. I was doing the happy-NAS dance because of it. Buying 4 at the same time makes sense when you do this since the best practice with RAID configurations usually have the same model of drive across the entire set so that there's no timing inconsistencies when writing data (which can foul up the RAID quickly). So I setup everything right. But on day 2, I had one of the drives fail on me - so said the NAS, so when I investigated it, it turns out that there were some sectors that were "bad enough" to warrant the NAS to taking the drive offline. I went through Amazon's replacement process (which is awesome, BTW) and once I dropped off the drive at the UPS store, a replacement one was FedEx'd to my house. I got it the next day. So it's better support than most IT companies frankly, and 10x better than CDW. I'm not sure how long non-Amazon tech businesses compete anymore; it's hard to beat that kind of service. The supplier was the one who sent it (not Amazon) and they did so so quickly and it came packaged so nice (it looks brand new in every way; if it didn't say 'renewed' in this listing, you'd never know). I put in the replacement drive and whallah - it works fine. Moral of the story: buying renewed drives can *feel* scary. But in my exhaustive experience buying harddrives - and I've been doing so for 35+ years (I bought MFM drives and would convert them to RLL just to get 1% extra storage back-in-the-day), even when you buy new ones, there's about a 10-20% chance that it's DOA. This is not a manufacturing problem per se - but imagine yourself in the life of a harddrive, these get kicked around by the sorting machines that the likes of UPS, USPS and FedEx use as well as LTL Freight services, so the mere fact that they work after being shipped is a miracle. So that said, I had the around the same luck with these drives as I do when buying new drives but here's why I actually think this is better: when there is a problem, at least the Amazon/Seller combo I used, you get a replacement drive *the next day*. When you buy a new one and go through the manufacturer - don't hold your breath as it's like 1-2 weeks. And while, yes, you could always buy a new one through Amazon and have a quicker turnaround, this is $100 cheaper per drive than buying new. So save your money, buy this drive, and realize that with any hard drive new/refurb/used, you will have the likelihood of it not working from the get-go.. at least buying this refurb here, you are actually getting better service for a lower cost, which is a total win for the customer. Lastly, these drives are performant and actually have superior stats to new ones of the exact same model! Especially if you are using them in a NAS, these are a no-brainer; and they power save and all of that stuff (and I didn't use the tape or had to convert the "pins" for an older setup but all of the stuff to do that is in the box when you buy it). A+++!

I buy 6x8TB per year for several years. This fall, I saw these 12TB's. I bought 2 because I use RAID1. As one cautious reviewer wrote, if one fails, you still have the other. I bought these 2 a few weeks before I left the country to work 6 months overseas. I wrote about a half TB to the pair to verify all was well. All was well. A few months after I got here (out of the country), it was time to try the pair. One was DOA. Left me with one. I didn't have a 2nd drive. Getting a replacement half way around the world out of the question. I thew a TB at the 2nd one to make sure it was working properly. Figured I'd copy the drive when I got back to the US. Bad idea. I had written a TB to it over the past few weeks in bursts of 200-300GB at a time, turning off the drive after I'd finished. I turned the drive on this morning to write another few hundred GB's. Drive not seen. Looked at disk management. It was there. Except it's there as 8TB and not initialized. I'm using the same docking bay, a CENMATE with raid support. I put the drive in an empty Startech bay I use infrequently. Same deal. Finally, I tried an Inatech. This one really blew me away. It reported an 8TB with a file structure from a drive I hadn't loaded in 2 months. Just thought I mention that to those of who have experienced 'wormholes' like this in your career. Where it's getting that structure from, I have no idea. Obviously when I click on a file in explorer, nothing opens. In summary, if 2 drives can fail, especially when the 2nd one contained data that I now have to spend 100 hours creating, my opinion, for what it's worth, is stay away from these 12TB drives. I've had 8TB's fail over the years but never, ever 2 in a row.

Looks good so far. Here're SMART details for my drives: ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000b 100 100 016 Pre-fail Always - 0 2 Throughput_Performance 0x0005 133 133 054 Pre-fail Offline - 92 3 Spin_Up_Time 0x0007 159 159 024 Pre-fail Always - 411 (Average 414) 4 Start_Stop_Count 0x0012 100 100 000 Old_age Always - 237 5 Reallocated_Sector_Ct 0x0033 100 100 005 Pre-fail Always - 0 7 Seek_Error_Rate 0x000b 100 100 067 Pre-fail Always - 0 8 Seek_Time_Performance 0x0005 140 140 020 Pre-fail Offline - 15 9 Power_On_Hours 0x0012 096 096 000 Old_age Always - 29268 10 Spin_Retry_Count 0x0013 100 100 060 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 21 22 Unknown_Attribute 0x0023 100 100 025 Pre-fail Always - 100 45 Unknown_Attribute 0x0023 100 100 001 Pre-fail Always - 1095233372415 192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 612 193 Load_Cycle_Count 0x0012 100 100 000 Old_age Always - 612 194 Temperature_Celsius 0x0002 176 176 000 Old_age Always - 34 (Min/Max 20/53) 196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always - 0 197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0008 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x000a 200 200 000 Old_age Always - 0 231 Temperature_Celsius 0x0032 100 100 000 Old_age Always - 0 241 Total_LBAs_Written 0x0012 100 100 000 Old_age Always - 4749305997574 242 Total_LBAs_Read 0x0012 100 100 000 Old_age Always - 3926456736852 ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE 1 Raw_Read_Error_Rate 0x000b 100 100 016 Pre-fail Always - 0 2 Throughput_Performance 0x0005 132 132 054 Pre-fail Offline - 96 3 Spin_Up_Time 0x0007 157 157 024 Pre-fail Always - 417 (Average 420) 4 Start_Stop_Count 0x0012 100 100 000 Old_age Always - 1240 5 Reallocated_Sector_Ct 0x0033 100 100 005 Pre-fail Always - 0 7 Seek_Error_Rate 0x000b 100 100 067 Pre-fail Always - 0 8 Seek_Time_Performance 0x0005 140 140 020 Pre-fail Offline - 15 9 Power_On_Hours 0x0012 096 096 000 Old_age Always - 31225 10 Spin_Retry_Count 0x0013 100 100 060 Pre-fail Always - 0 12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 1109 22 Unknown_Attribute 0x0023 100 100 025 Pre-fail Always - 100 45 Unknown_Attribute 0x0023 100 100 001 Pre-fail Always - 1095233372415 192 Power-Off_Retract_Count 0x0032 099 099 000 Old_age Always - 1742 193 Load_Cycle_Count 0x0012 099 099 000 Old_age Always - 1742 194 Temperature_Celsius 0x0002 181 181 000 Old_age Always - 33 (Min/Max 20/56) 196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always - 0 197 Current_Pending_Sector 0x0022 100 100 000 Old_age Always - 0 198 Offline_Uncorrectable 0x0008 100 100 000 Old_age Offline - 0 199 UDMA_CRC_Error_Count 0x000a 200 200 000 Old_age Always - 0 231 Temperature_Celsius 0x0032 100 100 000 Old_age Always - 0 241 Total_LBAs_Written 0x0012 100 100 000 Old_age Always - 4958856514087 242 Total_LBAs_Read 0x0012 100 100 000 Old_age Always - 3989414955916