Is MDD as Reliable as Seagate? Whose Drive It Is, and Whose Warranty Applies

The USPTO record, Backblaze's Q2 2026 Drive Stats and every MDD listing were read at source on 1 October 2026. Prices and counts last refreshed 2026-10-01

"Is MDD as reliable as Seagate" is one of the most-searched questions about this label, and it has a problem built in: it compares a drive maker with something that is not one. Seagate designs and builds hard drives and publishes failure-rate specifications for them. MDD is a name applied to drives, and the useful version of the question is underneath it - whose drive is this, and who stands behind it if it fails? Those we can answer from records, not opinions. Reliability we cannot, and the section on fleet data below explains why that is a finding rather than a gap we are hiding.

Whose drive is it? The registry record

Ownership of a trademark is a matter of public record. We do not rely on anyone's characterisation of who is behind MDD; we read the United States trademark register, most recently on 1 October 2026:

So an MDD drive is a drive sold under a label that GoHardDrive owns. The label has its own part numbers - MDD18TSATA25672E, MD20TSAS25672E and so on - which identify the product in GoHardDrive's range rather than the mechanism inside it. That distinction matters for every question on this page. A Seagate part number tells you exactly which drive you are buying and lets you look up Seagate's own specification for it. An MDD part number tells you which MDD product you are buying, and the listing may or may not say what is inside.

In practice it rarely does. When we read every MDD listing in our catalogue on 1 October 2026, one of 28 named the manufacturer part number it matched: an MDD 3TB SAS listing described itself as "well-matched to manufacturer part # ST3000NM0023", a Seagate part number. That is

Why there is no reliability data, and why we print none

We have no reliability figure for MDD and print none - not a score, not a comparison, not an implication. The largest public source of drive failure rates, Backblaze's quarterly Drive Stats, reports by drive model for the drives in its own data centres; its Q2 2026 tables list models from HGST, Seagate, Toshiba and WDC, and no model under the MDD label.

Press, attributed Q2 2026 Drive Stats: Hard Drive Failure Rates (models with > 500 drives and > 100,000 lifetime drive days in the lifetime table), Backblaze. Read 1 October 2026.

This is the discipline the whole page runs on. It would be easy to borrow a number - the failure rate of the Seagate model one listing says it matches, an average for "refurbished drives", a star rating - and present it as an answer. Each would be a figure about something other than the drive you are looking at. We would rather tell you what is unknown than give you a number that sounds like an answer and is not one.

Whose warranty applies

This is the part of the question that has a real answer, and it is the part that matters most if a drive fails. A new Seagate drive carries Seagate's warranty, tied to its serial number and honoured by Seagate. An MDD drive carries whatever warranty its listing states, and that warranty is the seller's. On 1 October 2026 we read what each MDD listing in our catalogue actually says: 9 of the active MDD listings we hold state a five-year warranty, 1 a three-year warranty, and 17 state none at all. Before that check our own records assumed five years for almost every MDD row; they now hold only what the listings say. GoHardDrive's published terms for purchases on its own site set a 15-day window for returning defective merchandise and say returns carry a restocking fee; they do not state a warranty length.

Company's own words goHardDrive.com Terms - return (RMA) policy for purchases made at goHardDrive.com, GOHARDDRIVE, INC.. Read 1 October 2026.

What the listings say about the drives

Everything below is what MDD listings state, read on 1 October 2026, and every item is the seller's claim rather than a specification we have verified:

• Spindle speed: all 28 listings say 7200 RPM.
• Recording technology: none says CMR or SMR, and our CMR/SMR resolver has no MDD part number on record, so we show it as unknown. Unknown is never treated as CMR on this site.
• Sector format: none states 512e or 4Kn.
• Construction: twelve mention a helium platform.
• Condition: of the 5 in-stock MDD listings whose titles we have re-read since 1 October, 4 say "(Renewed)".

Our own data: the renewed MDD that was our cheapest "new" drive

MDD's story on this site is also a story about our own mistake, and it belongs here. Amazon's data reports most "(Renewed)" listings as condition New, and until 30 September 2026 our title rules did not catch every case. An MDD 3TB SAS listing titled "(Renewed)" was recorded as new, and for months it was the cheapest new hard drive in our daily records - $11.33 per terabyte on our first day of history, 23 March 2026. Five of the twelve renewed or recertified listings we found stored as new were MDD. All are now stored as used and excluded from every new-drive figure; the full account is on refurbished vs recertified vs renewed. It is a clear example of the point of this page: the label and the data field said one thing, and the listing title said another.

MDD listings in stock now, with their evidence

Every MDD listing in stock on our tracker, one row per product, cheapest per terabyte first. The warranty column is what that listing states; the line under the condition is the evidence for that offer - Amazon's own condition and grade, the seller, the seller's note and the title's claim. Prices are Amazon US listings, in US dollars.

Provenance describes the offer shown now, not the drive: Amazon's own condition and grade, the seller, the seller's note in their words, and what the listing title claims. It can change when a different seller holds the listing.

In stock by capacity: 2TB (1), 3TB (2), 6TB (3), 10TB (1), 12TB (2), 14TB (1), 18TB (3), 20TB (2). Capacity pages exist where three or more are in stock.

Price against Seagate, measured like for like

Where both MDD and Seagate have a listing in stock at the same capacity, interface and condition, MDD averages +4.2% against Seagate per terabyte across 10 such matches (median -0.4%), and is the cheaper of the two in 5 of them. That is a price comparison only - it says nothing about reliability - and the full table, with what each side's warranty is, is on MDD vs Seagate.

What you can check yourself

The questions this page cannot answer from outside, you can answer once the drive is in your hands. Read its health data on arrival - power-on hours, reallocated and pending sectors - and compare it with what the listing said. Check the part number and capacity on the drive's own label against the listing. Keep the listing page and invoice, because a seller warranty is only as good as your proof of what was promised. Do all of it inside the return window.

Frequently asked questions

Related: MDD: who makes them · MDD warranty · Mixing MDD with IronWolf · MDD vs Seagate · Refurbished vs recertified vs renewed