Best Hard Drives for NAS – 2021

Choosing the Best Hard Drives for your NAS

For those of you that have decided to buy a NAS server for Home or business, choosing the right hard drive media to put inside can be incredibly difficult. NAS drives, much like the knives, spoons and forks in your cutlery drawer are all designed to be used for a specific situation (Have you ever used a ladle to stir a cup of tea?) and if you install unsuitable drive media in your NAS, then chances are it will impact both the performance and the efficiency of your system long term. In recent years, several HDD manufacturers have introduced dedicated server tailored hard drives (and SSD of course) that are better suited to the more sporadic access nature of NAS system storage, the 24×7 power on schedule, faster read/write switching internally and improved long term durability that is needed in these environments. However, with more than fifteen popular NAS and Data Center class drives currently on the market (and that is just the top tier), it can be remarkably confusing to narrow the choices down to your particular needs. So, today I want to help you choose the right NAS hard drives, the first time! Below I have detailed eight different kinds of NAS/Server architecture and which NAS hard drive is best suited for each.

Important Considerations in Buying Hard Drives for your NAS

Before going any further, it is important to understand that choosing the right NAS hard drive requires you to understand certain terms that are thrown around in the data storage industry – that way you KNOW that the drive you choose will perform the tasks you need to the best possible standard. Below are a few of the most important terms that you need to know in order to understand the marketing jargon that the HDD brands put out and understand the pros and cons of each:

RAID – Redundant Array of Independent Disks (also known as Redundant Array of Inexpensive Disks in the old days), RAID is the ability to use multiple NAS HDDs at once, the spread your data across them to improve capacity, speed and/or (most importantly) data safety. Unlike a backup (where a duplicate of data is kept in another location/system), RAID 0 combined the total storage available into 1 giant storage area for great performance, but no safety net if a drive breaks. RAID 1 effectively halves your total storage as a single visible drive, but allows you 1 drive of safety net. RAID 5 and RAID 6 allow 1 or 2 disk safety net respectively but also allow much, MUCH larger storage arrays. There are other RAID levels, but these are the most popular in the data storage industry.

SATA – The most common HDD connection in 2021 and allows up to a potential 6Gigabits per second throughput between the connected drive and the NAS system. However mechanical HDDs rarely exceed 280MB/s at the very, very top end. There are also connections such as SAS, NVMe and U.2. But there is far more enterprise and more recently apply to SSDs for the most part.

Saturation – This is the term (in data storage at least) used to describe how much data and flowing through an available interface/bandwidth. ie a SATA HDD can potentially allow 600MB/s of data performance, however, most NAS HDDs only give around 180-280MB/s because of their mechanical/moving-part design. So the saturation of SATA of a single drive would be much less at 180/280MB/s.

Platters – These are the spinning disks inside the HDD casing that hold all of the data. Larger capacity drives will feature more patters. Compression techniques used internally will generally allow more space, but only up to a point.

Rotation Speed – This is the reported speed that the platters spin at to allow the arm/actuator to search them and locate/write data magnetically.

Cache – This is an area of memory on the NAS Hard drive that compiles/distributes the data that is being gathered by the disk on the fly and sends it in all directions. The cache will generally be larger on bigger capacity NAS hard drives, as well as be larger on drives that feature Shingled Magnetic Recording (SMR) as the drive needs more handling space to apply data in this unique writing fashion.

Terabytes Written (TBW) – Generally applied as an annual figure, TBW is a rating given to a NAS Hard Drive to denote that this drive can receive X TBW a year and maintain performance. This figure factors in that you might fill and empty the drive repeatedly in the lifespan of the drive over and over (at Data centers or tiered backups for example). The higher the number, the better. Generally, you will fin standard NAS hard drives are 180TBW, Pro series are 300TBW and Enterprise-class HDDs are 550TBW or higher.

Magnetic Recording – This is the process of how data is applied to the platters on the disk. In recent years we have seen 5 types of recording rise to the top of NAS hard drive usage. SMR (Shingled Magnetic recording – the least popular). PMR/CMR (Perpendicular/conventional Magnetic Recording – by far the most popular and well known), EAMR (Energy Assisted Magnetic Recording – WD are using this in their much MUCH larger drives) and HAMR (Heat Assisted Magnetic Recording – Seagate are using this is THERE larger capacities). Each has its own advantages and disadvantages, but if in doubt, always go for PMR/CMR NAS hard drives.

Warranty Length – This is the length of time the manufacturer will provide a replacement/repair on your NAS hard drive in the event of it failing through no fault of your own. Generally ranging from 3-5years.

And there you have it. Those are the terms you should probably know in order to choose the best NAS hard drive for your system. So, let’s take a closer look at different NAS hardware Environments and recommend the best NAS hard drive for each.

Best Hard Drives for a Small NAS Drive – WD Red & WD Red Plus

1-14TB, 5400/7200RPM, 64-512MB Cache, 180TBW, 3yr Warranty, WD Red 1-6TB (SMR), WD Red Plus 1-14TB (CMR) $50-400  

If you are looking to populate a compact, modest powered, desktop NAS system (so a 1-Bay or 2-Bay NAS drive), then you have quite a large range of Hard Drives on offer. It is worth highlighting though that larger and more enterprise drives (i.e faster and longer warranty) will be noticeably noisier. Additionally, you will need to factor in that your maximum storage is going to be capped at either a single drive OR (in a 2-Bay NAS with RAID 1)  your storage halved to maintain redundancy. Fianlly, you will need to factor in that most 2-Bay NAS devices will either have a smaller external network connection (1/2.5Gbe) or are not really capable of saturating a full connection externally. So, baring these factors in mind, I would recommend the WD Red series of NAS hard drives for small NAS systems. They do not typically have more aggressive hardware internally, so the ambient noise when these drives are running will be remarkably low.

Sound Test Video Live Soon (Below)

The performance, due to the lower rotations per minute (RPM) and cache might not seem spectacularly high, but in a 1-Bay or 2-Bay NAS, you likely could not push much performance externally anyway, so why spend much more on something that in most cases you will not be able to take advantage of. Be warned though, as you reach the much higher capacities above 8TB, the general background noise of the drives will increase incrementally.

+ Affordable Price Tag

+ Low Noise and Power Consumption in 24×7 Use

+ Good base level of Capacities Available

– Some Drive feature Shingled Magnetic Recording (SMR)

– Performance is fairly average in the smaller capacities



Best Hard Drives for a RAID 5 Desktop 4-Bay NAS – Toshiba N300

4-16TB, 7200RPM, 128-512MB Cache, 180 TBW, 3yr Warranty, 1-1.2M MTBF Rating $250-450  

A 4-Bay NAS drive is generally when home and small/medium business users start to take their storage seriously. There are such a wide variety of hardware options that arrive at this storage tier, ranging from powerful Intel/AMD processors and DDR4 memory, to 10Gbe and PCIe upgrades. This arrives with the utility if RAID 5, that allows users to have a much larger potential capacity and performance, but still have a single drive of redundancy to fall back on in the event of drive failure. At this degree of NAS storage, you have a much greater potential to not only largely saturate a 10Gbe connection, but alternatively, you can also look into installing 2.5Gbe and 5Gbe upgrades and fill multiple plus gigabit connections directly or via a switch.  In order to maximize this connection, but to also not max out your budget, I recommend the Toshiba N300 range of Hard Drives. Although they are a brand that is generally held commercially in the 3rd place when it comes to NAS media drives, their N300 range arrives at a similar/lower price point than Seagate Ironwolf and WD Red, but also arrives with 7200RPM on all capacities, with the lowest capacity arriving with 128MB caching and scaling up to 256MB quickly in the series. The increase in RPM will increase the background clicks, hums and whirs of the drive, but at 4-Bays, this is something that the NAS enclosure itself will begin to generate too. A high performing and often overlooked drive that, at the top capacity, can hit performance of up to 274MB/s.

+ Well Priced for a 7200RPM and 128/256/512 Cache Drive

+ Available in up to 16TB

+ Error Recovery Control

– Will Generate More Noise at 7200RPM

– Not As Widely Available



Best Hard Drives for a RAID 6 Desktop 6/8-Bay NAS – Seagate Ironwolf

1-12TB, 5900-7200RPM, 64-256MB Cache, 180TBW, 3yr Warranty, Rescue Data Recovery Services Included $50-480  

For those that are looking at a NAS server for business, or are home users that have made the enterprising move into the Prosumer bracket, then a 6-Bay or 8-Bay desktop NAS solution will become incredibly attractive. At this storage tier, we find a number of very cool and incredibly useful features become more widely available. For a start, we find the utility of RAID 6 (the 2 disk safety net configuration) much more palatable, as it makes less of a dent on our total available storage. Additionally, at this storage size, we start to see much more powerful processors, such as the Intel Core (i3, i5, etc) series arrive, AMD Ryzen and even Xeons. This combined with huge expandability of both memory internally and storage externally and generally with 10Gbe included as standard or available as an upgrade. So, at this scale of NAS storage, the hard drive choice becomes more important, as you do not want to create an internal bottleneck. For this tier of storage, I recommend the Seagate Ironwolf range of NAS drives. They arrive with a large number of 7200RM drives (with 5400RPM in the smaller capacities), a 180 terabytes per year guaranteed workload and the Seagate Rescue service. For those that are not aware, the Seagate Rescue+ package is a data recovery service that is included with your Ironwolf and Ironwolf Pro drives that, alongside your 3 year warranty, includes an additional 3 years of data recovery services.

What that means is that if your drive fails through no fault of your own within reason (so, no, not smashing it with a hammer), you can send the drive off to the Seagate recovery labs and they will try to get that data back. From accidental deletion, all the way through to mechanical and forensic level recovery, this is an impressive inclusion! You should still factor other safety nets in your architecture (backups, UPS, RAID, etc) but given the cost of data recovery services (costing anything from hundreds to thousands of pounds), this is a very, VERY useful inclusion when you need it. Additionally, Seagate Ironwolf hard drives sill manage to be the most affordable NAS drives on the market compared with their competitors, even when including the Rescue recovery included. They are also the only 3rd party NAS hard drive brand that has a tool to monitor drive health available on practically ALL the NAS software GUIs in the market, in Seagate Ironwolf Health Management.

+ Excellent Price Point

+ Rescue Data Recovery Services

+ Seagate Ironwolf Health Management

+ ONLY CMR/PMR Drives in their NAS Range

– Max Drive Capacity is 12TB



Best Hard Drives for a Small Rackmount NAS – WD Red Pro

2-18TB, 7200RPM, 128-512MB Cache, 300TBW, 5yr Warranty $99-600  

Now we move onto the Rackmount NAS compatible hard drives, we have to start looking squarely at two main factors – Performance and Durability. If you are a business or established Prosumer user, then chances are that your NAS system is going to be used for a much larger % per day than most average users. Whether it is for surveillance, virtual machines, business file-sharing or just a combination of all of them every day, you want drives that are going to give you a good level of performance internally AND externally. Likewise, as the hard drives in even a modest rackmount NAS will be on for extended periods, you need to know that the drive can maintain the promising performance indefinitely AND without braking. This is where we start to look at specifications such as TBW (Terabytes Written), Mean time between failure, workload cycles and the warranty in more detail. For those looking at 10Gbe equipped or at least ’10Gbe Ready’ modest rackmount systems, I would recommend the WD Red Pro series of compatible NAS hard drives. Generally, one of the first Pro series NAS hard drives to arrive on the market, the WD Red Pro series is designed for NAS systems up to 24Bays and is available up to 18TB currently.

Sound Test Video Live Soon (Below)

Although certainly a noticeable degree louder in general noise level, you won’t hear it over the rackmount NAS anyway! Additionally, the WD Red Pro series using a similar degree of construction to the Ultrastar series, so you have fantastically enterprise drive that using helium seal technology to maintain optimal efficiency and all capacities feature a 300TB a year workload, over 5 years.

Certainly one of the most expensive NAS HDDs out there, but provides a very good level of storage, performance, durability and overall is a very dependable drive for SMB users (Small/Medium Business) that want a drive they can rely on.

+ Top Tier NAS Drive Performance

+ 300TB/Y Workload

+ Build for up to 24-Bay Servers

– Certainly Noiser than non-Pro equivalents

– More Expensive than the Seagate Pro Option



Best Hard Drives for an SMB Rackmount NAS 12-Bay – Seagate Ironwolf Pro

4-18TB, 7200RPM, 256MB Cache, 300 TBW, 5yr Warranty, Rescue Data Recovery Services Included $80-560  

When it comes to the move into Rackmount storage for businesses (novices stop here) then not only do you have to only consider Pro/Enterprise-class drives only, but you can also start to look at drives that include certain business level advantages in terms of coverage and service. Much like the non-PRO series of hard drives mentioned earlier, the Seagate Ironwolf Pro series of HDDs include the Rescue+ data recovery services but also includes an impressive 5 years of the manufacturers warranty. However, it is in terms of performance, capacity and durability that the difference between these two ranges become apparent. For a start, the Ironwolf Pro HDD range arrives in capacities of up to 18TB (20TB promised for later in 2021 thanks to Energy Assisted Magnetic Recording), with ALL drives in the PRO range arriving with 7200RPM and 256/512MB of cache. The result is that these drives will hit up to an impressive 260MB/s, which even in smaller RAID 5 groups will easily saturate a 10Gb connection with just 4-5 drives.

In recent years we have seen Seagate reshuffle their range of available capacities to align the capacities from 1-12TB to arrive in the standard Ironwolf range and Capacities of up to 18TB and 20TB to arrive on the PRO series (likely due to those larger capacity options requiring the more enterprise hardware as standard and making a non-PRO version impossible without purposely nerf’ing the lesser drives intentionally. There is crossover in 4-12TB models in between, however, the distinction in RPM, cache, build design and TBW rating is wide enough to justify this. The noise level of the Ironwolf HDD series in PRO is noticeable higher, but given these are designed for larger arrays, this noise increase will be less noticeable over the ambient noise of the whole system generally.

+ Excellent Price Point vs Ironwolf NON-Pro in the Portfolio

+ Rescue Data Recovery Services

+ Seagate Ironwolf Health Management

+ ONLY CMR/PMR Drives in their NAS Range

– Smallest Drive Capacity is 4TB

– Noticable Boot Up Noise



Best Hard Drives for an Enterprise Rackmount NAS Server – Seagate EXOS

1-18TB, 72000RPM, 256-512MB Cache, SAS & SATA Options, 550 TBW, 5yr Warranty, $80-460   

Now we finally move into the class of hard drive that is more classically defined at ‘Data Center’ and/or Hyperscale environments. Often choosing between a PRO class and Enterprise-class drive can be ticky at a glance. However, Pro class drives generally arrive with a much longer terabytes written rating per year (ie the amount of data that can be written to the drive throughout its lifespan per annum), arrive in numerous interfaces (so both SAS and SATA generally) and typically arrive with numerous format and encryption standard versions available. These are available because some industries and organizations insist on drive media that features in-built protection and secure erase on the drive itself. Of all the enterprise and data centre-class media in the market, I generally recommend the Seagate EXOS series for any hyper scale system environment. They are very, VERY closely followed by the Western Digital UltraStar class of drives, but the Seagate EXOS series is a little clearer to understand, has larger capacity options available earlier, will hopefully release Mach2 version drives in 2021 (dual actuator/arm SATA drives at 400MB/s+) and generally arrive a pinch lower in price too in like-for-like comparisons against the Ultrastar.

Sound Test Video Live Soon (Below)

Recent changes by Synology in their newest 2021 series of rackmounts systems to ONLY support their own range of HDD media has led to their own drives featuring on their own respective hardware, so make sure to check that your intended NAS rackmount system supports Seagate EXOS drives before you head to checkout!

+ Huge Range of Architecture Options (FIPS, Military Encryp, 4KN, SED, SAS and more)

+ Constantly Evolving (Mach 2 versions, x14, x16 & x18 etc)

+ Comparatively Lower in Price vs Ultrastar

– Range Can Be Confusing

– Noisy!



Best Hard Drives for a Business Synology NAS – Synology HAT5300

8-16TB, 7200RPM, 256/512MB Cache, 550TBW, 5yr Warranty, Synology System ONLY, Firmware Control on Synology DSM $250-450  

Arriving on the scene in Jan 2021, the Synology branded range of Hard drives for enterprise server use took ALOT of people by surprise! Synology has always had a long-standing reputation with the production of network-attached storage, so in efforts to produce a complete first-party storage system that includes the software, the network hardware AND the media inside is very what their brand has been all about. In their defence too, these are not just cash-grab drives and are in-fact enterprise-class drives that are being priced at PRO series drives (so an Ultrastar/EXOS drive that is at the price tag of a WD Red or Ironwolf Pro). The drives themselves arrive (at launch anyway) with just three capacities available (8TB, 12TB and 16TB) and the architecture of them is quite eye-catching. A 550TBW per year rating, a 2.5Million MTTF, 256/512MB cache and performance ranging across the capacities from 230MB/s to a reported 270MB/s+. The drives are originally Toshiba M06/07/08 Enterprise drives that have a tweaked Synology NAS firmware onboard, so they are geared specifically towards utilization inside the Synology ecosystem. You can even check and upgrade the individual drive firmware directly from with the Synology DSM graphical user interface too, which is quite a unique and convenient feature for those larger arrays with differing drive versions being installed throughout your server’s lifespan.


It is worth remembering however that the Synology HAT5300 range of NAS hard drives can ONLY be used in the Synology NAS hardware portfolio. Using them in other systems will likely result in your warranty coverage being invalid as you are using them in a configuration unsupported by Synology.


The move towards hard drive locking by Synology is something that has impressed some and disappointed others – but if you were going to be installing drive media inside a NAS system for business anyway, then ultimately these are still a very solid and well-performing product for you.

+ Enterprise Drives at a PRO class Price

+ 550TBW on ALL Capacities

+ Drive Firmware can be Updated from within the Synology DSM GUI

– Using them in not Synology NAS Hardware is not Supported

– Performance is a pinch lower than WD Red Pro (5-15MB/s)



Best Hard Drives for a Business QNAP NAS – WD Ultrastar

1-18TB, 7200RPM, 256-512MB Cache, 550TBW, 5yr Warranty, FIPS and SED Options, SATA, SAS and U.2 NVMe SSD Options $70-550  

Finally, we move onto possibly the most well known of the enterprise-class of Hard Drives on the market. When it comes to data center and hyper-scale storage environments, Western Digital’s UltraStar range has the same reputation and long-running recognition as IBM has in the computer industry. They have been the go-to drive media of choice in the huge storage environment’s for years, thanks in large part to the fact they have been designed, developed and improved at the same time as the systems they were going into. In recent years, competitors have taken chunks of the market from them (as they are a larger and slightly slower behemoth to suddenly change tactic) and feature larger product runs that have to last extensive lengths of time to facilitate data center replacement media as needed. Nevertheless, in recent years the Ultrastar brand under WD has diversified hugely and alongside the popular WD Gold label has branched into a vast array of interface types, form factors, media variants and scales. Typically the first drive series to crack into a new capacity tier (the first to crack 20TB too).

Sound Test Video Live Soon (Below)

The Ultrastar series of hard drives will often be compared against the WD Red Pro range of NAS hard drives when considering populating a server. It is worth remembering that the Ultrastar series is designed for both a higher performance AND a much more enduring performance – i.e it can maintain that level, as well as switch between processes, for much longer. Indeed in testing, the Ultrastar even features a much higher Read and Write performance than pretty much any other drive that peaks as high as 280MB/s in our ATTO DiskBenchmark testing below with just a single HDD. Even the IOs (IOPS_ went as high as 19,000, which although low when compared with modern high-end SSDs, for a single HDD is really impressive).

The drives themselves are fantastically dull in appearance of course, as one might expect from the enterprise tier and also feature quite an aggressive spin up noise. However, in much larger scale environments, you will almost certainly not hear the drive media over the ambient system fan noise. Overall still an oldie but a goodie!

+ Consistently High Performance

+ Well Establish HDD Drive and Brand

+ Numerous Interfaces, in-Drive Encryption Systems and Choices

– DEFINITELY one of the most confusing product ranges

– Noticeably Noisy at boot




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    2 thoughts on “Best Hard Drives for NAS – 2021

    1. I don’t think you address the SMR/CMR issue well enough with (in particular) the WD red drives for small NAS systems.

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