# Which external hard drive offers the largest storage capacity at a reasonable price? — Verified Specification Comparison

> All specification data verified from official manufacturer documentation.

Which external hard drive offers the largest storage capacity at a reasonable price?

## Products

### Western Digital WD Ultrastar DC HC680 28TB WD2820KK (external-ready)
```yaml
product: western-digital-wd-ultrastar-dc-hc680-28tb-wd2820kk-external-ready
brand: Western Digital
price_gbp: 745.14
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
warranty: 5 years
interface_type: SATA
transfer_speed: Up to 265 MB/s
storage_capacity: 28TB
```

- **Price:** £745.14 [^1]
- **Summary:** The Ultrastar DC HC680 is a 3.5in 28TB enterprise data-center HDD using SMR, 7200 RPM, OptiNAND and HelioSeal for very high capacity and improved efficiency; it's designed for cloud and hyperscale storage where high density and low cost per TB matter. It suits deployments that can tolerate SMR characteristics and require large, power-efficient archival storage.
- **Ideal For:** Ideal for buyers seeking the largest external-capacity drive at a reasonable price because it offers 28TB capacity and enterprise power efficiency (28TB, 7200 RPM, up to 265 MB/s).
- **Additional Sources:** [^2], [^1], [^2]

### Seagate Expansion External Desktop Drive 28TB STKP28000400
```yaml
product: seagate-expansion-external-desktop-drive-28tb-stkp28000400
brand: Seagate
price_gbp: 633.38
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
weight: 1176 g
warranty: 1 year limited warranty
dimensions: 178.75 mm x 41.90 mm
power_supply: External power adapter (included)
interface_type: USB 3.0 (USB-C cable included)
storage_capacity: 28 TB
```

- **Price:** £633.38 [^3]
- **Summary:** The Seagate Expansion 28TB STKP28000400 is a high-capacity desktop external HDD with USB 3.0 connectivity and an external power adapter, designed for large media libraries, backups, and bulk storage. It offers plug-and-play setup for Windows and macOS and includes Rescue Data Recovery Services and a limited warranty.
- **Ideal For:** Ideal for users seeking the largest single-drive external capacity at a reasonable price because it provides 28 TB of storage with USB 3.0 connectivity and an external power adapter.
- **Additional Sources:** [^4], [^5], [^3], [^4], [^5]

### Seagate Seagate Exos X30 External 30TB ST30000NM003G
```yaml
product: seagate-seagate-exos-x30-external-30tb-st30000nm003g
brand: Seagate
price_gbp: 894.18
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
warranty: 5-Year
dimensions: 147.00mm x 101.85mm x 26.10mm
interface_type: SATA 6 Gb/s
transfer_speed: 275 MB/s
storage_capacity: 30TB
```

- **Price:** £894.18 [^6]
- **Summary:** The Seagate Exos X30 30TB is an enterprise-class, high-density 3.5 in HDD using HAMR/Mozaic technology to deliver very large single-drive capacity with 7200 RPM performance and a 512MB cache. It targets data centers and heavy-duty storage arrays where maximizing capacity per bay and sustained transfer rates matter. It includes enterprise features like Seagate Secure and a five-year warranty.
- **Ideal For:** Ideal for this question because it offers the largest single-drive capacity at 30TB with sustained transfer speeds around 275 MB/s and enterprise reliability, giving maximum storage per drive at a competitive enterprise price.
- **Additional Sources:** [^7], [^6], [^7]

---
## References & Sources
[^1]: Western Digital Store, accessed 2026-06-16. https://www.westerndigital.com/products/internal-drives/data-center-drives/ultrastar-dc-hc680-hdd?sku=0F62904
[^2]: Newegg, accessed 2026-06-16. https://www.newegg.com/p/pl?d=wd+ultrastar+28tb
[^3]: Seagate, accessed 2026-06-16. https://www.seagate.com/products/external-hard-drives/expansion-desktop-hard-drive/
[^4]: Best Buy, accessed 2026-06-16. https://www.bestbuy.com/product/seagate-expansion-28tb-external-usb-3-0-desktop-hard-drive-with-rescue-data-recovery-services-black/J37C5H54V9
[^5]: FirstShop, accessed 2026-06-16. https://www.firstshop.co.za/products/seagate-3-5-inch-28tb-expansion-external-hdd-stkp28000400-326853
[^6]: CDW, accessed 2026-06-16. https://www.cdw.com/product/seagate-exos-m-st30000nm004k-hard-drive-enterprise-30-tb-sata-6gb-s/8246468
[^7]: Newegg, accessed 2026-06-16. https://www.newegg.com/seagate-exos-m-st30000nm004k-30tb-hard-drive-for-enterprise-storage-7200-rpm/p/N82E16822185114