The best nas drive today is the MDD 20TB SATA 7200RPM NAS at $499.99 ($25.00/TB), as of 2026-08-19.
Recomputed every refresh · last updated · 90 listings in the field
The MDD 20TB SATA 7200RPM NAS takes it at $25.00/TB against the runner-up's $28.33/TB - a margin of $3.33/TB, or 13.3%. That gap is computed, not asserted: it is the arithmetic difference between the two cheapest qualifying listings we hold, and it is the whole of the reason one is above the other.
It sits in a field of 90 qualifying listings. It is new stock, CMR recording, SATA-6G.
Best = lowest cost per terabyte among in-stock, CMR-verified, known-brand SATA drives of 4TB or larger, sold new. SAS is excluded because a consumer NAS cannot use it. Not a benchmark ranking.
Most "best drive" pages do not tell you what best meant, which makes them impossible to argue with and therefore impossible to trust. Ours is one sentence and you can reject it: if you would rather optimise for warranty length, for a specific manufacturer, or for the lowest absolute price rather than the lowest price per unit, the full field is ranked below and you can take a different row knowing exactly what you are trading.
What the criterion deliberately excludes: any drive whose recording technology we could not confirm - unknown is not treated as CMR, any seller we do not recognise, and anything out of stock at the moment the page rendered. SAS drives are excluded here because they need a host bus adapter and a backplane that a desktop or consumer NAS does not have.
| # | Drive | Capacity | Price | Per TB | |
|---|---|---|---|---|---|
| WINNER | MDD 20TB SATA 7200RPM NAS | 20TB | $499.99 | $25.00 | Buy |
| 2 | WD Ultrastar 12TB SATA HUH721212ALE601 | 12TB | $339.99 | $28.33 | Buy |
| 3 | Seagate Exos X22 22TB | 22TB | $649.99 | $29.55 | Buy |
| 4 | WD Ultrastar 24TB SATA WUH722424ALE6L4 | 24TB | $749.99 | $31.25 | Buy |
| 5 | WD Ultrastar 14TB SATA WUH721414ALE6L4 | 14TB | $499.99 | $35.71 | Buy |
We log the winner only when it CHANGES, and we show the model and the date - not what it cost at the time. A past price attributed to a specific listing is exactly the thing our Amazon display policy does not permit us to render, so the log carries the fact and the date and stops there. That is still the part no written-once article can produce.
Anyone filling a consumer or prosumer NAS - Synology, QNAP, UGREEN, TerraMaster, Asustor - where the bays are SATA, the machine runs continuously, and a rebuild has to complete without drama.
It applies the constraint the whole-market crown ignores: SATA only. That single restriction changes the answer at most moments, because the cheapest terabytes in the catalogue are SAS drives a NAS cannot use, and a crown that names one is useless to the person asking this question.
Worth knowing: The cheapest qualifying drive is not always a NAS-branded one. Desktop drives that pass our CMR and brand gates appear here, and what you trade for the lower price is error-recovery firmware and a vibration rating rather than capacity.
The 90 qualifying listings run from $25.00/TB to $95.83/TB, a spread of $70.83/TB between the cheapest and dearest drive that meets the same standard. That spread is worth looking at before you act on the verdict: a tight field means the market has settled and the winner is a few percent ahead of an equivalent product, while a wide one means the drives differ in something the criterion does not capture - usually product line, warranty term or how long the listing has been sitting.
5 brands are represented. More than one manufacturer competing at the same specification is what makes the cheapest listing meaningful rather than incidental.
The median listing in this field sits at $49.28/TB, 97% above the winner. Because this page ranks across 14 different capacities, the per-unit figure is doing real work: the cheapest terabyte and the cheapest drive are not the same listing here.
A NAS drive is a drive that will tolerate running continuously, rebuild without dropping out of the array, and fit the bay. This ranking enforces the parts of that we can verify across a whole catalogue: SATA interface, CMR recording, in stock, from a brand we recognise. It cannot verify vibration tolerance or firmware error-recovery behaviour, and those are real differences between NAS-branded lines and desktop drives.
Recording technology is the one that has actually cost people data. A shingled drive in a rebuilding array can slow to the point where the rebuild takes over a week, and some controllers time out and eject the drive - turning a single-drive failure into a second one. Every drive in this ranking is CMR-verified, and drives whose recording technology we could not confirm are excluded rather than assumed safe.
Error recovery control is the difference you cannot see here. Desktop drives try hard to recover a bad sector, sometimes for minutes; a RAID controller interprets that silence as a dead drive. NAS and enterprise firmware gives up quickly and lets the array handle it. Cheap desktop drives appear in this ranking when they qualify on our criteria, and this is what you are trading for the lower price.
The other half of the decision is how many drives, which is a different question from which drive. Filling a four-bay box with the cheapest terabyte and filling it with the best value per terabyte produce different bills and different capacities, and our fill pages price both for every NAS we track.
It is a price-and-fitness answer and nothing more. We do not run a test lab, we publish no read or write figures, and there is no claim anywhere on this page that one drive is faster than another. Ranking storage by speed requires measuring it, and anyone who does should tell you how; we would rather rank on what a catalogue can actually observe every few hours.
It also cannot tell you how a manufacturer handles a warranty claim, how loud a drive is in a room you sit in, or whether a particular batch had a bad year. Those are the things a review is for. What this page does that a review cannot is stay correct: it is recomputed when you load it, and the field it beat is printed underneath so you can see the answer being earned rather than asserted.
This page gives one answer. If you want the full catalogue rather than a verdict, these are the pages that carry it:
What it costs to fill a NAS · NAS drives · Every verdict we publish · Where prices are heading · CMR/SMR list
MDD 20TB SATA 7200RPM NAS, at $499.99 ($25.00/TB). That is the lowest cost per terabyte among the 90 listings that meet the criteria on this page, read from our catalogue at the moment you loaded it. It is a price-and-fitness verdict rather than a performance one - we run no test lab and this page makes no speed claim about any drive.
We have been logging the winner for this page since 2026-08-19, and every change since then is listed above with its date. The honest answer is that it depends on how deep the field is: a capacity with fifteen competing listings changes hands often, one with three barely moves. That log is the thing a written-once article cannot produce, and it is why this page exists in this form.
Because the criterion is cost per terabyte, not brand reputation, and it is printed on this page precisely so you can disagree with it. Every drive in the field passes a brand gate - we will not name an unrecognised seller as an answer - but among drives that pass, the cheapest terabyte wins. If you value a specific manufacturer's warranty handling or a particular product line, the full field below is ranked and you can pick a different row with the trade-off visible.
No, and this is the most important limitation on the page. We do not benchmark drives, we do not publish read or write figures, and nothing here claims one drive is faster than another. What we can measure is price, availability, capacity, interface and recording technology, so the verdict is built from those. Anyone ranking drives by speed should tell you how they measured; we would rather rank on what we can actually observe.
How much weight the verdict carries. 90 listings meet the criteria right now. That is a deep field: several sellers are competing and the winner earned it against real alternatives.