The Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) costs $0.0361/GB while the WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP costs $0.0469/GB. Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) offers 23% better value per gigabyte as of August 2026. Both products are available on BuyPerUnit with prices from Amazon, Best Buy, and Newegg.
Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) vs WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP — Which Is Better Value?
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Specification Comparison
| Spec | Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) | WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP |
|---|---|---|
| Brand | Seagate | Western Digital |
| Capacity | 18TB | 18TB |
| $/GB | $0.0361 | $0.0469 |
| Price | $650.00 | $844.99 |
| Retailer | Newegg | Newegg |
| Category | Hard Drives (HDD) | Hard Drives (HDD) |
| Subcategory | hdd | hdd |
Price Across Retailers
Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D)
Which Should You Buy?
Based on current pricing data, the Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) offers better value at $0.0361//GB compared to the WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP at $0.0469//GB — that's roughly 23% less per gigabyte.
The best deal for the Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) is $650.00 at Newegg, while the WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP starts at $844.99 at Newegg.
However, price per gigabyte isn't everything — consider factors like warranty, performance specs, brand reliability, and your specific capacity needs. Check each Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) and WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP product page for detailed specifications and price history.
Frequently Asked Questions
Is Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) or WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP a better deal?
As of August 2026, Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) offers better value at $0.0361//GB compared to WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP at $0.0469//GB. That is approximately 23% better value per gigabyte.
What is the price per GB of Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D)?
The Seagate Exos X20 ST18000NM003D 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive (ST18000NM003D) is currently priced at $0.0361/GB ($650.00 for 18TB) at Newegg.
Where can I buy WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP for the cheapest price?
The cheapest price for the WD Purple Pro 18TB 7200 RPM 512MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive - WD181PURP is $844.99 at Newegg, which works out to $0.0469/GB.