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Seagate Exos vs WD Ultrastar

Exos and Ultrastar are the two dominant enterprise HDD families for datacenter, homelab, and high-capacity server storage. Both are rated for 24/7 operation, carry 5-year warranties at retail, and are designed for multi-drive chassis with vibration tolerance. In practice the choice often comes down to price at the capacity you need, firmware compatibility with your HBA or backplane, and whether you prefer Seagate or WD support.

Quick comparison

Exos (Seagate) and Ultrastar (WD/HGST legacy) both target the same workloads: always-on servers, JBODs, and storage arrays. Exos X-series tops out at 24 TB with helium-sealed models; Ultrastar HC-series reaches similar capacities. Both offer SAS and SATA interfaces. Workload ratings are typically 550 TB/year, with 2.5M-hour MTBF. For most buyers, the lowest price per TB at your target capacity is the right pick.

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

Seagate Exos — Current Prices

New Seagate Exos enterprise drives sorted by price per terabyte. Includes Exos X-series helium models across all available capacities.

£18.05/TB New

Seagate Exos 7E8 HDD 512E/4KN SAS

8 TB Internal 3.5" SAS
£144.40 Amazon UK· 3h 14m
£20.90/TB New

Seagate Exos X14 ST10000NM0478 - Hard drive - 10 TB - internal - 3.5" - SATA 6Gb/s - 7200 rpm - buffer: 256 MB

14 TB Internal 3.5" SATA
£292.60 Amazon UK· 43m
$22.50/TB New

Seagate Exos X10 Enterprise Hard Drive ST10000NM0096 10 TB - SAS 12Gb/s

10 TB Internal 3.5" SAS
$225.00 Amazon US· 3h 10m
$23.33/TB New

Seagate Enterprise ST3000NM0025 3TB 7200RPM SAS 12.0 GB/s 128MB 512n Enterprise Hard Drive (3.5 inch, Exos 7E8 HDD 512N SAS)

3 TB Internal 3.5" SAS
$69.99 Amazon US· 1h 1m
£24.62/TB New

Seagate Exos 7E10 8TB Internal Hard Drive HDD - 3.5 Inch 512e/4Kn SAS 6GB/s, 7.200 RPM, 256MB Cache and 2M MTBF for Enterprise, Data Centre (ST8000NM017B)

8 TB Internal 3.5" SAS
£196.99 Amazon UK· 1h 14m
$24.92/TB New

Seagate Exos X24 24TB internal server Hard drive ST24000NM000C 3.5" HDD SATA3 512MB 7200RPM

24 TB Internal 3.5" SATA
$598.00 Amazon US· 9h 9m
$25.00/TB New

Seagate Exos X14 ST12000NM0008 12 TB Hard Drive - 3.5" Internal - SATA (SATA/600)

12 TB Internal 3.5" SATA
$299.99 Amazon US· 3h 27m
$25.00/TB New

Seagate Exos X24 3.5" Internal Hard Drive - 20TB, Single, SATA III 6 Gb/s

20 TB Internal 3.5" SATA
$499.99 Amazon US· 5h 37m

WD Ultrastar — Current Prices

New Western Digital Ultrastar enterprise drives sorted by price per terabyte. The Ultrastar HC-series carries on the HGST legacy of reliability.

$21.88/TB New

HGST Ultrastar DC HC320 HUS728T8TAL5204 8 TB Hard Drive - 3.5 Internal - SAS [12Gb/s SAS]

8 TB Internal 3.5" SAS
$175.00 Amazon US· 2h 24m
£27.90/TB New

Western Digital Ultrastar DC HC330 3.5" 10000 GB Serial ATA III

10 TB Internal 3.5" SATA
£279.00 Amazon UK· 1h 58m
$29.08/TB New

HGST Ultrastar He12 HUH721212AL4201 12 TB Hard Drive - SAS [12Gb/s SAS] - 3.5 Drive - Internal

12 TB Internal 3.5" SAS
$349.00 Amazon US· 3h 53m
$29.52/TB New

Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5 Internal - SATA

18 TB Internal 3.5" SATA
$531.45 Amazon US· 2h 44m
$30.00/TB New

WD WUS721010ALE6L4 Ultrastar DC HC330 0B42266 10TB 7200 RPM SATA 6Gb/s 256MB Cache 3.5-Inch Enterprise Hard Drive

10 TB Internal 3.5" SATA
$299.99 Amazon US· 4h 20m
$30.00/TB New

WD-40 Ultrastar HE12 12TB SAS 512E

12 TB Internal 3.5" SAS
$360.00 Amazon US· 3h 55m
$30.00/TB New

WD-40 Ultrastar HE12 12TB SAS 512E

12 TB Internal 3.5" SAS
$360.00 Amazon US· 3h 55m
$30.55/TB New

Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5" Internal - SATA

18 TB Internal 3.5" SATA
$549.99 Amazon US· 2h 24m

High-Capacity Enterprise (14 TB+)

The largest enterprise drives from both families. More terabytes per slot means fewer bays, fewer HBAs, and lower power per usable TB.

£20.90/TB New

Seagate Exos X14 ST10000NM0478 - Hard drive - 10 TB - internal - 3.5" - SATA 6Gb/s - 7200 rpm - buffer: 256 MB

14 TB Internal 3.5" SATA
£292.60 Amazon UK· 43m
$24.92/TB New

Seagate Exos X24 24TB internal server Hard drive ST24000NM000C 3.5" HDD SATA3 512MB 7200RPM

24 TB Internal 3.5" SATA
$598.00 Amazon US· 9h 9m
$25.00/TB New

Seagate Exos X24 3.5" Internal Hard Drive - 20TB, Single, SATA III 6 Gb/s

20 TB Internal 3.5" SATA
$499.99 Amazon US· 5h 37m
$25.00/TB New

Seagate Exos X24 24TB Enterprise Internal Hard Drive HDD - 6GB/s SATA 7200RPM 2.5M MTBF (ST24000NM002H)

24 TB Internal 2.5" SATA
$599.99 Amazon US· 5h 47m
£27.19/TB New

Seagate Exos X18 Enterprise Class, 18TB, Enterprise Internal Hard Drive, SATA, 3,5" 6Gbit/s, 128MB cache ((ST18000NM000J)

18 TB Internal 3.5" SATA
£489.40 Amazon UK· 1h
$29.52/TB New

Western Digital Ultrastar DC HC550 18 TB Hard Drive - 3.5 Internal - SATA

18 TB Internal 3.5" SATA
$531.45 Amazon US· 2h 44m
$29.94/TB New

Seagate Exos X16 ST16000NM003G 16 TB Hard Drive - Internal - SATA (SATA/600)

16 TB Internal 3.5" SATA
$479.00 Amazon US· 2h 52m
$30.33/TB New

Seagate Exos X18 ST16000NM001J 16 TB Hard Drive - Internal - SATA (SATA/600) - Video Surveillance System, Storage System Device Supported - 7200rpm - Hot Pluggable - 512e/4Kn Format

16 TB Internal 3.5" SATA
$485.23 Amazon US· 1h 57m

Refurbished Exos & Ultrastar

Recertified datacenter pulls from both brands. Enterprise drives are designed for 2M+ hour MTBF, so a drive with 20-40K hours of use still has substantial life — ideal for homelabs and non-critical storage.

Why this matters: Refurbished enterprise drives often deliver the lowest price per TB available. Look for sellers that include SMART reports or a seller warranty. Drives with low reallocated sector counts and under 40,000 power-on hours are typically good candidates.

£18.18/TB Used

Seagate EXOS X22 22TB Interne Server Festplatte ST22000NM000C 3,5 Zoll HDD SATA 6Gb/s 7200RPM SED 512E 512MB Cache (Renewed)

22 TB External 3.5" SATA
£399.99 Amazon UK· 1h 41m
$18.33/TB Used

HGST, a Western Digital Company Ultrastar 7K6000 6000GB 7200RPM SAS 512E Ultra SE 128MB Cache 3.5-Inch Internal Bare or OEM Drives 0F22811

6 TB Internal 3.5" SAS
$109.99 Amazon US· 1h 29m
£18.33/TB Used

Seagate EXOS X24 24TB Interne Festplatte 3.5 Zoll SATA 3 Gbit/s 512 MB, ST24000NM000C (Renewed)

24 TB Internal 3.5" SATA
£439.99 Amazon UK· 2m
$20.00/TB Used

Western Digital Ultrastar DC HC530 WUH721414ALN604 0F31102 14TB 7.2K RPM SATA 6Gb/s 4Kn Power Disable HDD (Renewed)

14 TB Internal 3.5" SATA
$279.99 Amazon US· 1d 19h
$20.00/TB Used

ST14000NM0048 Seagate 14TB SAS 12 Gb/s (Not SATA) Exos X14 (New with Warranty) 3.5 Inch 7200 RPM 256MB Cache 512e 4Kn Enterprise Hard Drive HDD

14 TB Internal 3.5" SAS
$280.00 Amazon US· 3h 10m
£21.11/TB Used

Seagate Exos X18 Enterprise Class, 18TB, Enterprise Internal Hard Drive, SATA, 3,5" 6Gbit/s, 128MB cache ((ST18000NM000J)

18 TB Internal 3.5" SATA
£379.99 Amazon UK· 1h
$21.13/TB Used

Seagate Exos 7E8 8TB 7200 RPM Nearline SAS 3.5-Inch Enterprise Hard Drive (ST8000NM0075) (Renewed)

8 TB Internal 3.5" SAS
$169.00 Amazon US· 3h 26m
$21.17/TB Used

Seagate Exos X18 18TB SAS 12Gb/s 7200RPM 3.5" Enterprise Hard Drive - ST18000NM005J (Renewed)

18 TB Internal 3.5" SAS
$381.00 Amazon US· 7m