What is an enterprise hard drive, and do you need one?

What is an enterprise hard drive?

An enterprise hard drive is a drive its maker positions for servers, storage arrays and data centres, and backs with stated figures for that use. Seagate describes its Exos range as 'Engineered for modern data centres'. Toshiba calls its MG series ideal for enterprise storage arrays and industrial server systems, and rates it for 24/7 operation at a workload of 550 TB/year.

The word is the makers' own. We have not found a document that defines 'enterprise' as a formal standard, so the useful test is what a range states rather than what it is called. Three lines settle most of it:

• Workload: how much data the maker rates the drive for, and whether it states round-the-clock use. Toshiba's MG figure is 550 TB/year, 24/7, and WD rates the Ultrastar DC HC590 for 550TB/year workloads.
• Warranty: Toshiba states a 5-year warranty for the MG series, and Seagate lists a 5-year limited warranty on the Exos 7E10.
• Interface: some enterprise ranges are sold in both. The MG series has 6 Gbit/s SATA and dual-port 12 Gbit/s SAS options, and Seagate lists the Exos 7E10 in SATA and SAS.

We hold no WD Gold specification, so no WD Gold figure appears here, whatever WD Gold rows the table shows.

Enterprise hard drive vs consumer hard drive: what to set side by side

We hold no sourced specification for any desktop or consumer range, so this page prints no head-to-head numbers for them. What we can give you is the enterprise half of the comparison, and the line to look up on the drive you are weighing it against.

For enterprise hard drives vs desktop drives, Seagate's support note gives the plainest steer we hold. It says SAS drives are designed for continuous use, and that for 24x7 use a desktop drive would not be ideal. The same note says SAS drives cannot be plugged into SATA controllers, so a SAS enterprise drive is no use on an ordinary desktop SATA port. A SATA enterprise model at least matches the port, and then the question becomes whether you would pay for a rating your machine may never call on.

Enterprise hard drive for NAS, or a NAS drive?

The same rule opens the enterprise hard drive vs NAS question. An ordinary SATA port in a NAS will not take a SAS model, on Seagate's rule, so start by confirming which interface the NAS has. If it is SATA, only the SATA rows in the table below are candidates.

Beyond that we stop short. We hold no NAS maker figure for workload or failure, so we cannot tell you that one class outlasts the other. We have also gathered no NAS maker's compatibility list for this page, so we make no claim that any enterprise drive works in any particular NAS. Look for the exact part number on the NAS maker's own list.

SAS or SATA enterprise drive: reading the Interface column

Because one range can come in both interfaces, the range name alone does not tell you which you are looking at. Seagate lists Exos 7E10 models separately by interface, at capacities up to 10 TB, and Toshiba offers both across the MG series. Go by the Interface column and the part number. An n/s in that column means we could not read that value from the listing, so confirm it there before you order. Seagate's rule runs one way only: SATA drives may be plugged into SAS controllers. SAS vs SATA and SATA enterprise hard drives take the split further.

Enterprise hard drives for sale on Amazon.co.uk: the full new class

This table holds the 88 new 3.5-inch listings we class as enterprise and currently find in stock, SATA and SAS together, lowest price per TB first. The lowest is £23.04/TB, on Seagate Exos 26TB Internal Hard Drive at £599.00, inc VAT. We do not sell any of these: each row links to the listing on Amazon.co.uk.

Some things are deliberately missing. Used and refurbished listings belong with refurbished enterprise hard drives. 2.5-inch enterprise drives are out, and so is any listing for which we hold no form factor. Older enterprise-class listings with no assigned product line are not in this class either. A row with no stated capacity has no per-TB figure.

Enterprise hard drive 4 TB, 8 TB and 12 TB: new listings by size

Within a single capacity, price per TB and price rank the rows identically. So these three tables show what a headline rate hides: the actual outlay at that size, and how interface and seller differ across it. Seagate's Exos data sheet gives a part number to look for at each size.

At 4 TB we currently find 12 new listings, the lowest at £161.72. Seagate's sheet lists ST4000NM024B in SATA and ST4000NM025B in SAS.

At 8 TB the count is 10, from £368.75. The same sheet lists ST8000NM017B in SATA and ST8000NM018B in SAS, so one capacity can mean two different drives.

At 12 TB the count is 10, from £324.17. Seagate's sheet lists ST12000NM002H in SATA and ST12000NM007H in SAS. Toshiba gives the MG range as 1 TB to 24 TB. Larger sizes, with drive counts for buying in quantity, sit on the data centre page.

What new means for warranty, and who you claim against

The warranty figures above describe new ranges, which is one reason this table is new only. Seagate's recertified drives have a six-month warranty, and the new-drive term does not carry across, so a cheaper refurbished row is not the same purchase at a lower price.

The maker's warranty is also separate from your rights against the seller: Which? puts a faulty-goods breach with the retailer that sold the drive. On Amazon.co.uk the seller may not be the manufacturer. The where-to-buy guide goes through what to look for on the listing.

We have not found a document from Seagate or Toshiba that states how their warranty applies to a given Amazon.co.uk marketplace offer. Ask the seller, and keep the answer.