HDD|Hunt

WD vs Seagate: Reliability & Price Comparison

Western Digital and Seagate are the only two major HDD manufacturers left. Both make excellent drives, but their product lines, warranty policies, and pricing strategies differ. This page puts their drives side by side so you can compare real prices and make an informed choice instead of relying on brand loyalty.

The reliability question

Backblaze publishes quarterly drive failure data from their datacenter fleet. As of 2025–2026, both WD and Seagate enterprise drives show annual failure rates between 0.5–2.5% depending on model and age. No brand has a decisive reliability edge — individual model selection matters more than the logo on the label.

Quick Verdict

Who this is for
NAS builders, server admins, and storage shoppers trying to decide between WD and Seagate product lines.
What usually wins
Compare specific models, not brands. WD Red Plus vs Seagate IronWolf, WD Ultrastar vs Seagate Exos — pick whichever is cheaper at your target capacity. Both are reliable when used within their rated workloads.
Prioritise
Price per TB for equivalent-tier drives. Then warranty length and workload rating for your specific use case.

Prices updated hourly from Amazon US and UK. All links go directly to the retailer. Details.

Western Digital Drives — Best Prices

WD hard drives across all product lines ranked by price per TB.

£18.47/TB New

WD Purple SATA - Festplatte - Serial ATA (WD34PURZ)

8 TB Internal 3.5" SATA
£147.74 Amazon UK· 11h 4m
£19.54/TB New

WD 18TB Elements Desktop External Hard Drive - USB 3.0, Black

18 TB External 3.5" USB
£351.77 Amazon UK· 54m
£20.50/TB New

Western Digital WD WUH721818AL5204 18TB SAS 12Gb/s 7.2K RPM 512M 0F38353 512e/4Kn SE HDD

18 TB Internal 3.5" SAS
£369.00 Amazon UK· 3h 15m
£20.61/TB New

WD 22TB Elements External Hard Drive, Desktop HDD storage, USB 3.0 compatible, Fast Transfer rates, Easy add on storage for all your pictures, videos, music and documents, Black

22 TB External 3.5" USB
£453.50 Amazon UK· 7m
£20.76/TB New

WD 20TB Elements External Hard Drive, Desktop HDD storage, USB 3.0 compatible, Fast Transfer rates, Plug-and-play storage for all your pictures, videos, music and documents, Black

20 TB External 3.5" USB
£415.23 Amazon UK· 1h 27m
£22.08/TB New

WD 24TB Elements External Desktop Hard Drive, USB 3.1 Gen 1, Fast transfer rates, Easy add on storage for all your pictures, videos, music and documents, Black

24 TB External 3.5" USB
£529.99 Amazon UK· 3h 48m
£22.12/TB New

WD 16TB Elements External Hard Drive, Desktop HDD storage, USB 3.0 compatible, Fast Transfer rates, Easy add on storage for all your pictures, videos, music and documents, Black

16 TB External 3.5" USB
£353.99 Amazon UK· 1h 48m
£23.22/TB New

WD Elements 18TB Desktop USB 3.0 External Hard Drive with the SanDisk Ultra 256GB USB 3.0 Flash Drive

18 TB External 3.5" USB
£417.99 Amazon UK· 3h 2m

Seagate Drives — Best Prices

Seagate hard drives across all product lines ranked by price per TB.

£12.19/TB New

Seagate IronWolf ST4000VN008 4TB Internal Hard Drive, NAS HDD, 3.5 Inch, 5900 rpm, CMR, 64 MB Cache, SATA 6 GB/s, Silver, 3 Years Data Rescue Service

16 TB Internal 3.5" SATA
£195.00 Amazon UK· 3h 19m
£18.05/TB New

Seagate Exos 7E8 HDD 512E/4KN SAS

8 TB Internal 3.5" SAS
£144.40 Amazon UK· 3h 18m
£18.75/TB New

Seagate Expansion Desktop External 16TB

16 TB External 3.5" USB
£299.99 Amazon UK· 3h 16m
$19.15/TB New

Seagate Enterprise Capacity 3.5 HDD (Constellation ES) 4TB 7200RPM

6 TB Internal 3.5" SAS
$114.90 Amazon US· 2h 45m
$20.91/TB New

Seagate Expansion 22TB External Hard Drive HDD - USB 3.0, with Rescue Data Recovery Services (STKP22000400)

22 TB External 3.5" USB
$459.99 Amazon US· 18h 5m
£21.04/TB New

Seagate Expansion Desktop 12TB, External Hard Drive, USB 3.0, Data Rescue Services (STKP12000400)

12 TB External 3.5" USB
£252.52 Amazon UK· 53m
£21.25/TB New

Seagate ST3000NM0023 - 3TB 7200RPM 3.5 SAS ENT HDD

4 TB Internal 3.5" SAS
£85.00 Amazon UK· 3h 30m
£22.45/TB New

Seagate Expansion Desktop 20TB, External Hard Drive, USB 3.0, Data Rescue Services (STKP20000400)

20 TB External 3.5" USB
£449.00 Amazon UK· 1h 27m

Refurbished Enterprise — WD Ultrastar vs Seagate Exos

Recertified datacenter pulls from both brands — the cheapest high-capacity drives available.

£15.38/TB Used

ModusTech External (DESKTOP) Hard Drive 3TB USB 3.0 & Type-C 3.0 - High-Speed Data Storage for PC, Mac, Laptops, and Gaming Consoles - Durable Design, Compatible with Windows, MacOS, Linux (16.0, TB)

16 TB External 3.5" USB
£246.05 Amazon UK· 2h 5m
$16.67/TB Used

MDD MAXDIGITALDATA X18 MACH.2 (Dual Actuator) 18TB 7200RPM SAS 12Gb/s 512MB Cache 3.5-Inch Enterprise Hard Drive (MDD18TSAS51272E-2X18) - [Not a SATA HDD] (Renewed)

18 TB Internal 3.5" SAS
$299.99 Amazon US· 8h 42m
$17.50/TB Used

HEWLETT PACKARD HUH728080AL5204-HPE 8TB 7.2K 12G LFF SAS Hard Drive

8 TB Internal 3.5" SAS
$140.00 Amazon US· 1h 54m
£17.72/TB Used

Western Digital HDD Gold 18 TB SATA 512 MB 3.5 Inch

18 TB Internal 3.5" SATA
£319.00 Amazon UK· 2h 6m
$17.74/TB Used

BUFFALO Replacement Spare Hard Drive 8TB NAS-Grade for TeraStation 2/4/8 Bay (OP-HD8.0N)

8 TB Internal 3.5" SATA
$141.90 Amazon US· 2h 14m
$17.86/TB Used

MDD MAXDIGITALDATA MDD (MD14TSAS25672E-2X14) 14TB 7200RPM 256MB Cache 4KN SAS 12Gb/s 3.5-inch (Dual Actuator) Enterprise Hard Drive - [NOT a SATA HDD] (Renewed)

14 TB Internal 3.5" SAS
$249.99 Amazon US· 18h 4m
£17.92/TB Used

Seagate Expansion Desktop 20TB, External Hard Drive, USB 3.0, Data Rescue Services (STKP20000400)

20 TB External 3.5" USB
£358.32 Amazon UK· 1h 27m
£18.27/TB Used

Seagate Exos 26TB Internal Hard Drive, 3.5 Inch HDD, SATA3, 256MB Cache (Renewed)

26 TB Internal 3.5" SATA
£475.06 Amazon UK· 2h 45m

How to Choose

Here is how the two brands compare across the factors that actually matter.

NAS drives

WD Red Plus (CMR) competes with Seagate IronWolf. Both are rated for 1–8 bay NAS use with 180 TB/year workload. Pricing fluctuates — check both and buy whichever is cheaper at your target capacity.

Enterprise drives

WD Ultrastar competes with Seagate Exos. Both offer 5-year warranties, 550 TB/year workload ratings, and vibration sensors for high-density enclosures. Refurbished Exos and Ultrastar drives dominate the used market.

Warranty and RMA

Both brands offer similar warranty terms (2–3 years consumer, 5 years enterprise/Pro). RMA experiences vary by region. Check warranty transfer policies if buying from third-party sellers — some warranties are non-transferable.

Recording technology

Both brands use SMR in some consumer models. Always verify CMR vs SMR for your specific model — brand alone does not guarantee recording technology. NAS and enterprise lines from both brands are CMR.