The WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black costs $0.0453/GB while the Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) costs $0.0279/GB. Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) offers 38% better value per gigabyte as of July 2026. Both products are available on BuyPerUnit with prices from Amazon, Best Buy, and Newegg.
WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black vs Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) — Which Is Better Value?
WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black
Specification Comparison
| Spec | WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black | Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) |
|---|---|---|
| Brand | Western Digital | Seagate |
| Capacity | 18TB | 20TB |
| $/GB | $0.0453 | $0.0279 |
| Price | $814.99 | $559.00 |
| Retailer | Newegg | Newegg |
| Category | Hard Drives (HDD) | Hard Drives (HDD) |
| Subcategory | hdd | hdd |
Price Across Retailers
Which Should You Buy?
Based on current pricing data, the Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) offers better value at $0.0279//GB compared to the WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black at $0.0453//GB — that's roughly 38% less per gigabyte.
The best deal for the Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) is $559.00 at Newegg, while the WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black starts at $814.99 at Newegg.
However, price per gigabyte isn't everything — consider factors like warranty, performance specs, brand reliability, and your specific capacity needs. Check each WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black and Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) product page for detailed specifications and price history.
Frequently Asked Questions
Is WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black or Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) a better deal?
As of July 2026, Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) offers better value at $0.0279//GB compared to WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black at $0.0453//GB. That is approximately 38% better value per gigabyte.
What is the price per GB of WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black?
The WD My Book 18TB USB 3.0, Micro-B External Desktop Hard Drive Black is currently priced at $0.0453/GB ($814.99 for 18TB) at Newegg.
Where can I buy Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) for the cheapest price?
The cheapest price for the Seagate Exos X20z ST20000NM001J 20TB 7.2K RPM SATA 6Gb/s 3.5 (HOST MANAGED SMR) is $559.00 at Newegg, which works out to $0.0279/GB.