Recording method and stated workload rating are what separate these from desktop drives
Drives sold for a NAS differ from desktop drives in ways the makers publish plainly, and the differences repay reading because the price gap is real. The first is the recording method. Conventional recording, CMR, writes tracks side by side; shingled recording, SMR, overlaps them for density and rewrites neighboring tracks when data changes, which behaves quite differently under sustained writing. Some makers print it in the title and some leave it off the listing entirely — four of the models here state it and three do not — and inside a multi-drive enclosure that answer changes what happens while an array rebuilds. The second is the stated workload rating, published in terabytes written and read per year, which describes the duty the drive is specified for and is not a countdown to anything. Beside it sits MTBF, a population statistic in hours that says nothing about one particular drive, and the warranty, a commercial term. Three different things, and none of them a lifespan. Then the ordinary figures. Capacity is published in terabytes of a thousand billion bytes each, which is why a drive appears smaller once an operating system displays it in units of 1024; nothing is missing, the two are different units for the same count of bytes, and the figure quoted here is the maker's in the maker's unit. Rotational speed in revolutions per minute, cache size, the SATA interface, and whether the drive is helium-sealed, which changes power and heat at the large capacities. Vibration tolerance is published for multi-bay use. We compare capacity, recording method, stated workload rating, rotational speed, cache size, interface, warranty length, stated MTBF, stated idle power and stated acoustic figure.
4 TB · CMR · 5400 rpm · 64 MB cache · 180 MB/s · 1 million hours MTBF · three-year warranty with data recovery · up to 8 bays
A four-terabyte, 5400 rpm CMR drive that publishes its cache, a transfer rate, an MTBF and a three-year warranty with data recovery — and no workload rating.
Best for: A two- or four-bay home NAS where a stated warranty and a data recovery service matter more than the lowest price per terabyte.
≈ $260
14 TB · CMR · 300 TB a year · 256 MB cache · 1.2 million hours · five years plus three of recovery · 24 bays · no rpm figure
The largest capacity, the longest warranty and the highest bay ceiling on this shelf, and the cheapest terabyte among the new drives here at $45.07 on Amazon.com on October 26, 2026 — on a page that publishes no rotational speed.
Best for: A NAS of any size, up to 24 bays, where the largest drive, the longest warranty and the lowest price per terabyte on this shelf all point the same way.
≈ $631
8 TB · CMR · 7200 rpm · 256 MB cache · 1 million hours MTBF · 210 MB/s · 5 to 70 °C (41 to 158 °F) · no warranty term
An eight-terabyte, 7200 rpm CMR drive that publishes an operating temperature range nothing else here gives, and no warranty term at all where its four-terabyte sibling names three years.
Best for: An eight-bay NAS or smaller where 7200 rpm and 8 TB per drive are wanted — once the warranty has been confirmed with the seller.
≈ $500
4 TB · CMR · 5400 rpm · 128 MB cache · SATA 6 Gb/s · up to 8 bays · no MTBF, no warranty term
A four-terabyte, 5400 rpm CMR drive with 128 MB of cache, the cheapest drive on this shelf at $194.99 on Amazon.com on October 26, 2026, whose bullets name a warranty without giving its length.
Best for: A two- or four-bay home NAS where the lowest price for a CMR drive matters most.
≈ $195
12 TB · CMR · 180 TB a year with the formula published · 7200 rpm · 512 MB cache · three years · interface printed two ways
The only drive on this shelf that publishes how its workload rating is calculated, with the largest cache here, and the most expensive terabyte on the shelf.
Best for: An eight-bay NAS or smaller rebuilding large arrays, where 7200 rpm, a large cache and a published workload figure are wanted.
≈ $789
4 TB · 5700 rpm · 64 MB cache · SATA 6 Gb/s · 800,000 hours MTBF · refurbished with no operating hours · recording method not published
A refurbished four-terabyte drive that publishes a rotational speed, a cache figure and an MTBF, and that names neither its recording method nor any warranty term.
Best for: A bulk volume in a multi-drive enclosure where the workload is light and steady, bought by someone who has already decided how they will handle a failure.
No Amazon.com offer on October 26, 2026
4 TB renewed · CMR · 550 TB a year · 7200 rpm · 256 MB with non-volatile cache · 512e sectors · 2 million hours · no warranty term
A renewed enterprise drive carrying the highest workload rating and the highest MTBF on this shelf, and no warranty term of any kind to stand behind either figure.
Best for: A spare or a cold-storage drive for a buyer who accepts a renewed drive without a stated warranty, once an offer is listed again.
No Amazon.com offer on October 26, 2026
Capacity decides the total volume reachable, because the enclosure’s bay count will not change.
The stated MTBF is a manufacturer’s figure, computed under its own assumptions. This site reports it without turning it into a lifetime promise.
The stated rotational speed describes the platter’s regime. It is published on every product page.
A drive the maker declares intended for continuous operation in a multi-drive enclosure. Three drives on this shelf publish a workload rating in terabytes a year.
How tracks are written on the platter. It is published because it changes the behavior under sustained writing.
It is a statistical figure published by the maker. This site reports it without drawing an individual forecast from it.
The volume of data the maker declares over a given period. It is a usage commitment, not an observed physical limit.
It affects access time, heat and noise. Every drive here prints it except the IronWolf Pro, which gives a transfer rate instead.
The rules for combining them depend on the enclosure and the volume chosen. This site publishes drive characteristics.
For absorbing writes and speeding up some reads. Its size is published.
No: a warranty replaces the drive. The Seagate IronWolf 4 TB and IronWolf Pro add three years of Rescue data recovery, which is the only cover for data on this shelf.
Capacity sets the volume, the stated workload rating says what the maker will commit to, and the recording method decides the behavior on the day a rebuild is needed.
The table shows only the data published by four devices in five. Under that threshold, a column compares empty fields.
| Model | Price | Cache size | Capacity | Interface | Recording method |
|---|---|---|---|---|---|
| Western Digital WD40EFZZ | $195 | 128 MB — printed in the title | 4 TB — printed in the title, in the maker’s unit, and reported here in that unit without conversion | SATA at 6 Gb/s — printed in the title | CMR — printed in the title |
| Seagate ST4000VN006 | $260 | 64 MB — printed in the title. The second bullet's "up to 256MB" is the range ceiling | 4 TB — printed in the title. The second bullet also prints 16 TB, which is the ceiling of the IronWolf range and not this drive | SATA at 6 Gb/s — printed in the title | CMR — printed in the title |
| Seagate IronWolf ST8000VNZ022 | $500 | 256 MB — printed plainly in the title as the model’s figure. The second bullet gives the same number as "cache of up to 256MB", in the form of a ceiling, which is the less useful of the two statements | 8 TB — printed in the title and in the second bullet, in the maker’s unit and reported here unchanged | SATA at 6 Gb/s — printed in the title, in gigabits, which is the correct unit for SATA III | CMR — printed in the title. Conventional recording writes tracks side by side and does not rewrite neighbors when data changes, which is what decides how an array rebuild behaves |
| Seagate IronWolf Pro ST14000NEZ008 | $631 | 256 MB — printed in the title. The WD Red Plus 12 TB on this shelf gives 512 MB | 14 TB — printed in the title and in the second bullet, in the maker’s unit and reported here unchanged. It is the largest capacity on this shelf | SATA at 6 Gb/s — printed in the title, in gigabits, which is the correct unit for SATA III | CMR — printed in the title. Conventional recording writes tracks side by side rather than overlapping them, so changing data does not force neighboring tracks to be rewritten, which is what decides how a rebuild behaves in a large array |
| Western Digital WD Red Plus WD120EFBX | $789 | 512 MB — printed in the title, the largest on this shelf; the next is 256 MB | 12 TB — printed in the title, in the maker’s unit, and reported here in that unit without conversion. The first bullet also prints 1-14 TB, which is the span of the range rather than this drive | SATA, published two ways and not consistently — the title prints "SATA 6 GB/s" in gigabytes and the first bullet prints "Data Transfer Rate:6Gbps" in gigabits. SATA III runs at 6 gigabits per second, so the two differ by a factor of eight and the page never resolves them | CMR — printed in the title |
| Hitachi Ultrastar DC HC310 HUS726T4TALE6L4 | — | 256 MB, with a non-volatile cache named alongside it — stated in the fourth bullet, which describes the non-volatile part as improving write performance and protecting data. No other listing on this shelf names a non-volatile cache | 4 TB — printed in the title, in the maker’s unit and reported here unchanged. The first bullet describes it as high-density storage per drive bay | SATA at 6 Gb/s, with 512e sector emulation — printed in the title and named again in the second bullet. 512e means four-kilobyte physical sectors presented to the host as 512-byte ones; the refurbished MegaScale on this shelf publishes the same format | CMR, written out as conventional magnetic recording — stated in the third bullet, offered for consistent write performance under write-intensive workloads. It is the only listing on this shelf that spells the term out rather than printing the abbreviation alone |
| Hitachi HMS5C4040BLE640-FR-cr | — | 64 MB — printed in the title | 4 TB — printed in the title, in the maker’s unit. The figure is reported here as published and is not converted into any other unit | SATA at 6 Gb/s — printed in the title and named again in the second bullet as a 6 Gbit/s SATA interface | Not published on the listing — neither CMR nor SMR appears in the title or in the two bullets, on a drive whose rotational speed, cache and interface are all printed. It is the answer that decides how the drive behaves under sustained writing, and it is the one figure missing from an otherwise detailed title |
Specifications: manufacturer sheets for network and storage gear and the matching Amazon product pages. Prices and availability: Keepa. Every figure in this table names its source.
Most recent revision in this category: October 26, 2026.
Every price named in a summary was read on the date that review carries. What a shop asks today is shown beside the product, and it moves.
