Western Digital 12TB WD Red Pro NAS Internal Hard Drive HDD - 7200 RPM, SATA 6 Gb/s, CMR, 256 MB Cache, 3.5" - WD121KFBX
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This item is eligible for return within 30 days of receipt
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Availability:
Only 3 left in stock, order soon!
Arrives
Jun 4 – Jun 6
Capacity: 12TB
Features
- Available in capacities ranging from 2 to 22TB(1) | (1) 1GB = 1 billion bytes and 1TB = 1 trillion bytes. Actual user capacity may be less depending on operating environment.
- For RAID-optimized NAS systems with unlimited number of bays
- Rated for 550TB/yr workload rate(2) | (2) Annualized Workload Rate = TB transferred x (8760 / recorded power-on hours). The maximum rated workload is specified for operating at typical temperature of 40C. Workload Rate will vary depending on your hardware and software components and configurations.
- Designed to handle the demands of high-intensity 24x7 multi-user NAS environments
- Western Digital partners with a wide range of NAS system vendors for extensive testing to ensure compatibility with most NAS enclosures
Description
Designed specifically with medium or large scale business customers in mind, WD Red Pro drives are available for up to 24-bay NAS systems. Engineered to handle high-intensity workloads in 24x7 environments, WD Red Pro is ideal for archiving and sharing, as well as RAID array rebuilding on extended operating systems such as ZFS or other file systems. These drives add value to your business by enabling your employees to quickly share their files and back-up folders reliably in your NAS solution.
Digital Storage Capacity: 12 TB
Hard Disk Interface: Serial ATA
Connectivity Technology: SATA
Brand: WD
Special Feature: Data Recovery Service
Hard Disk Form Factor: 3.5 Inches
Hard Disk Description: Mechanical Hard Disk
Compatible Devices: Desktop
Installation Type: Internal Hard Drive
Color: Red
Digital Storage Capacity: 12 TB
Hard Disk Interface: Serial ATA
Connectivity Technology: SATA
Additional Features: Data Recovery Service
Hard Disk Form Factor: 3.5 Inches
Compatible Devices: Desktop
Hard Disk Rotational Speed: 7200 RPM
Specific Uses For Product: Business, Personal
Read Speed: 445 Bytes Per Second
Cache Memory Installed Size: 256
Data Transfer Rate: 240 Megabits Per Second
Form Factor: 3.5-inch
Hardware Connectivity: SATA 6.0 Gb/s
Hardware Platform: Mac, PC
Hard-Drive Size: 12 TB
Item Weight: 0.05 Kilograms
Item Dimensions L x W x Thickness: 5.79"L x 4"W x 1.03"Th
Number of Items: 1
Unit Count: 1.0 Count
Customer Package Type: Standard Packaging
Brand: WD
Model Number: WD121KFBX
Hard Disk Description: Mechanical Hard Disk
Built-In Media: HDD
Model Name: WD Red Pro
Manufacturer: Western Digital
Global Trade Identification Number: 46
UPC: 718037866246
Mfr Part Number: WD121KFBX
Item Type Name: Hard Disk Drive
Warranty Description: 5-year limited manufacturer
Installation Type: Internal Hard Drive
Color: Red
Enclosure Material: Hard drive components
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Jun 4 – Jun 6
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Capacity: 4TB
Using 2, 4TB drives in a home RAID array for photos, videos, etc. Main drive is an SSD but decided to go with these for bulk storage as they are a bit cheaper (guessing my last time buying HDD's and next time will just use SSD's because they are just so much faster). Drives seems to perform nicely and other than a little HDD noise here and there don't find them bothersome at all. Previously had 2, 2TB of these red drives in a RAID array (had it running for about 8 years) and never had any issues. In our office we have Gold versions of these running on a backup server for about 6 years with no issues. All in all, very reliable. Speed is fine, but obviously not going to compare to SSD. One thing about size of the drives which I see some comments on... The size of the 4TB drive is going to be approximately 4 trillion bytes (mine is 4,000,765,177,856 bytes), however your system will likely report that as 3.64 TB or 3.726 GB. The reason for this is that Windows computes 1GB as equal to 1,073,741,824 bytes and 1TB as equal to 1,099,511,627,776 bytes. These numbers are achieved by raising 2 to an increasingly greater power till you get your first number in the billions and then trillions. There is some technical reason why this is done, but ultimately it is just confusing as it creates 2 different ways of computing size. One, counting the actual number of bytes and the other, dividing your bytes by one of those numbers to get the amount of GB's or TB's. For MB the number Windows uses is 1,048,576 bytes (for example a 20,000,0000 byte file will be reported as 20,000,000 / 1,048,576 = 19.07MB). In any case, here is a summary of the approx drives sizes and around what Windows will report the size as (assuming the drives sizes represent actual bytes exactly, so 4TB for this calculation will be 4,000,000,000 bytes and not the number my computer showed above... so expect the actual numbers to be slightly higher than these): 2TB Drive = 1.82TB or 1,862.65GB 4TB Drive = 3.64TB or 3,725.29GB 6TB Drive = 5.46TB or 5,587.94GB 8TB Drive = 7.28TB or 7,450.58GB 10TB Drive = 9.09TB or 9,313.23GB 20TB Drive = 18.19TB or 18,626.45GB Hope this clears up some confusion here.
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Reviewed in the United States on May 18, 2023 by matt1234
Capacity: 20TB
I bought two units of the 20TB version of this WD Red Pro drive for my new storage system. I particularly went with the 20TB version, because - according to the datasheet on Western Digital's website - it is less noisy than some of the lower capacity models. I tested one of the units, not in my storage system, but in my open bench USB 3.0 to SATA Adapter (with a max transfer rate of over 500MBps). It performed well, the sequential read and write speeds as high as ca. 270 MBps and ca. 130 MBps on the low-side. This is typical of all HDDs: on the outside of the drive they can pack more data on one track than on the inside, so on each rotation they can write and read more data on the outside area of each disk platter. The write and read tests were also successful, no bad blocks were reported. For some performance figures, please see the attached screenshots (which have the serial number removed/redacted). Please note that the CrystalDiskMark results are performed on an empty HDD, so they seem to be executed in the "fast" section of the drive. The other graphs were taken from HDSentinel, relevant there are the bottom graphs, which show transfer rates across the surface of the drive. The sound of my test unit was also pleasant enough, the clicking wasn't too bothersome. But since I will move this drive into the case of my storage system very soon, the clicking will be a lot less noticeable than it is already. One action I always perform, BEFORE opening the product box of an HDD or SDD is to check the serial number on the box against the manufacturer's warranty website to ensure that the item is covered by the manufacturer's warranty. I do this both when amazon is the seller and when a 3rd party is the seller and amazon is just the fulfillment party. (I do not buy HDDs from a 3rd party seller that does not have fulfillment with amazon.) This is to avoid OEM/gray-market units that aren't covered by the manufacturer's warranty. A store warranty by a 3rd party seller is of no use to me, since these sellers come and go and I also don't want the hassle of dealing with them. Since the Red Pro series offers a manufacturer's warranty of 5 years, and HDDs fail frequently enough to make such a warranty very valuable, I always insist getting the manufacturer's warranty and even will query 3rd party sellers, if their stock with amazon is covered by such a warranty. As it turned out, the serial number of second 20TB HDD that I ordered (from a 3rd party seller, since amazon themselves were out of stock) did not show up in the manufacturer's database for U.S. warranty, so I can only assume that it is a gray-market unit and I immediately returned it. (I can only hope that the 3rd party seller will have to bear the full cost of this return, since I emailed them and asked about the manufacturer's warranty, before the item ever shipped, but they didn't answer my question.) One more tip: There has been some research that failure rates of HDDs from the same batch are somewhat correlated, so I always try to space out my purchases (either in time or by using different vendors) to increase the chance that I will be getting units from different batches. That's why I bought from two different 3rd party sellers on amazon (one of which apparently sold a grey-market unit), without disclosing that fact ahead of time.
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Reviewed in the United States on January 11, 2025 Reviewed in the United States on January 11, 2025 by tangofan
Capacity: 20TB
TL;DR: Western Digital 20TB WD Red Pro: A whisper-quiet, storage powerhouse for home NAS systems, effortlessly reliable. Imagine finding the holy grail of storage solutions for your home NAS setup. Enter the Western Digital 20TB WD Red Pro NAS Internal Hard Drive. This behemoth of a drive isn't just about its massive 20TB capacity; it's a symphony of quiet efficiency and steadfast performance. The drive hums along like a silent ninja, a much-appreciated trait for any home system. Its insides are where the magic happens, integrating into my NAS setup like a dream, showcasing its prowess with every task thrown at it. Setting this up was a walk in the park, user-friendly enough for even the most tech-averse. It's like having a friendly storage wizard guiding you through the process, whether you're aiming to safeguard precious family data or just giving your digital library room to grow. With five of these titans in my NAS, I'm swimming in a sea of storage space. It's like having your own digital Fort Knox, reliable and unflinching. WD has been a constant companion in my tech journey, and the Red Pro series upholds that legacy with aplomb. In short, the Western Digital 20TB WD Red Pro is like the Rolls Royce of NAS hard drives – luxurious in capacity, whisper-quiet in operation, and reliable to its core. For anyone seeking the pinnacle of storage solutions, this is it. WD Red Pro doesn't just meet expectations; it sails right past them into the stratosphere.
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Reviewed in the United States on January 20, 2024 by Chicago Ben
Capacity: 20TB
Great value for the money, plug and play with Synology. Good value for price per TB.
Reviewed in the United States on March 19, 2026 by Jeffrey
Capacity: 4TB
I purchased the 4T version for home PC with a windows operating system. I need this particular HDD because it is listed 7200RPM. I didn't meet any challenge when I installed other WD hard drives. It involved only a few clicks when I switched from WD 1T to 2T months ago, for example. I simply inserted the new disk into a USB case and cloned the entire disk in Minitool participation and got the job done. I was not lucky with this disk. It gave me so much trouble and wasted my two days to figure this out. First, sector size was different from my old 2t WD Blue drive thus I couldn't clone it directly. Because the target drive was not the main OS drive so I decided to simply copy all the folders into the new HDD and switch the two. Then I used Minitool to format it. It refused the command, software reported error. I then tried all other software including the one recommended on WD website (Acronis True Image for Western Digital). I finally got it done by using EaseUS. I formatted it and copied all folders from the old disk and switched it with the old internal disk. When I opened windows, none of the partitions created in EaseUS showed up. HDD showed up in BIOS menu so I knew it was there. I googled answer to this problem, read all articles to educate myself. Checked "Manage disk" in OS and realized one of the partitions was listed as GPT protective partition. I then followed the article published on Seagate website (ironic) and cleaned the entire disk using diskpat command. All data were removed. I returned to day 1. If your partition software doesn't work in Windows, check whether this disk is GPT protective in disk management. Don't repeat my mistake. I am glad I didn't do anything harmful to the old drive thus I spent the second day repeating what I did before, copy and paste. Now the new drive works and it works faster than old WD blue 2T. It is quite noisy but not scary. I am satisfied with the product so far but I hope WD can improve the product to meet various needs from customers. I am not a tech guy but switching HDD shouldn't be so difficult and time-consuming, thus I removed one star (should have been two stars when I felt frustrated yesterday).
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Reviewed in the United States on November 28, 2021 by Amazon Customer
Capacity: 24TB
These drives are always good. Just wish Amazon would package them a little better.
Reviewed in the United States on February 18, 2026 by James DeRoest
Capacity: 8TB
I purchased several of these for a custom NAS setup. They work perfect for this
Reviewed in the United States on January 15, 2026 by Ryan
Capacity: 10TB
Drive APPEARS to be USED but was sold as NEW. I've been buying WD HDD's since 1993 and have since talked to many WD employees on the phone. They've said that from the factory all HDD's are packed in anti-static bags with their logo on the bag and a very distinctive clean and straight heat seal mark. They also used to include a desiccant pouch in the bag to ensure any moisture that may have gotten in was absorbed, currently though they're not included. Also they have rules on how they must and must not be packaged for shipment. Amazon, as seller and shipper, have always packaged HDD's as per Western Digitals specifications. The sellers to be wary of, are Marketplace sellers. I started computing in 1983 with a Commodore 64. Back then I was in the United States Navy and for a time attached to the Aviation Intermediate Maintenance Department (AIMD) which supported The multi-million dollar aircraft 'Lockheed Orion P3C update 2&3'. I talked to Electronics Technicians (ET's) in the Micro-Min shop where they removed and replaced chips on Printed Circuit Boards (PCB's) and was made aware of ESD which today stands for Electrostatic-Discharge, but many of the Techs used 'Electrostatic Sensitive Device' for the acronym, which is just as true. As it turns out some chips, CMOS and smaller tech devices, can be destroyed by static electricity much lower in voltage/amperage than can be felt by humans walking across a carpet in the winter and touching a door knob and other such situations, so less than a human can sense. Which is why all HDD's are shipped from the factory in anti-static bags, because touching the drives PCB or the electrical connection pins could damage the drive. This is actually true of all computer components. This is an edit: You should always use a proper ESD safe wrist-strap when handling any computer component. You attach it to ground and should have jumper wires attached to all component grounding areas that you are currently working on. This is to ensure that all grounds are at the same electrical potential. Only handle cards (PCB's) on the edge, never on the contacts. Never touch any of the semiconductors on the PCB. Most modern HDD's have a relatively thin top made of stainless steel that has been stamped out of sheet SS with dented areas so as to make it more rigid. But you still don't want to handle them in that area. The infamous 'click of death' is due to unequal torqued pressure on the screws that afix the top to the cast/milled main body. The cast metal portion is the only portion that you should ever handle during installation whether it be a case drive bay or a quick release sled (docking bay). Apparently you can buy a mini torque device to re-torque the screws to the proper value, however note that the specification can change between different manufactures and models. So it's best not to not chance disturbing the torqued value from the factory. I only ever touch the cast portions (sides) of the drives, and have never had any problems with WD Drives, accept for a few DOA's that just wouldn't run. I've never had a clicking drive. I've been buying WD drives Exclusively since 1994. To give you an example of how many drives I've purchased, I have 15 computers running daily and 4 are either multi drive NAS's or NAS backups. Even though modern drives park the heads during shut down they should always be handled with kid-gloves, especially don't bump the case while the computer is running, though their arms are relatively stiff, the 'flying' heads can be made to impact the disks thus creating HARD errors on the surface. You'll probably never recover that data. Everyone building computers must be made aware of these facts, because manufacturers should not end up responsible for the mistakes of computer builders due to ignorance. It can only serve to drive up prices for their products and the cost to Amazon for logistics pertaining to unnecessary returns. Not to mention the down time of the builders awaiting a replacement part. I use these facts to ensure a HDD is in fact New and undamaged. The drive in question, that I'm reviewing, came in a generic Anti-Static bag and was sealed by a cheap heat sealer. The question everyone must ask themselves, that believe in data security, accuracy and reliability and their warranty, is: "why would anyone remove a HDD from it's original factory anti-static bag, then buy a generic anti-static bag and a cheap heat-sealer, then re-package it and sell it as NEW?" While these facts don't necessarily mean conclusively that the drive is used, one has to wonder why anyone would do all that. Probability? Possibility? Who want's to be sure? I would say a smart buyer would. I returned this drive to the seller, which cost me time, fuel and unnecessary wear and tear on my vehicle. Not to mention the cost to Amazon and the seller. Sellers have to remain honest! I bought this drive from "ALL4COMPUTERS," The UPS RETURN "proof of delivery" page said returned to "RESIDENTIAL". As I'm sure, everyone wants to get what they pay for. And no one likes scams or people that will try and cheat them. Always ensure that you are indeed getting NEW products when in fact that is what you've been told they are. As if not sure, you could end up as an ignorant loser. Ignorant: MW Definition: "lacking knowledge or comprehension of the thing specified". It's not derogatory as some believe. I'm ignorant of a great many things. Knowledge is power, so seek it and you shall learn and never be fooled again. Of course these facts are only being said for those that are unaware, for those 'in-the-know', ignore all the above advice. And please don't be offended, this has been for all those that are affected.
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Reviewed in the United States on January 15, 2025 by EssenceOfBeing