The WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) costs $0.0353/GB while the Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive costs $0.0400/GB. WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) offers 12% better value per gigabyte as of July 2026. Both products are available on BuyPerUnit with prices from Amazon, Best Buy, and Newegg.
WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) vs Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive — Which Is Better Value?
Specification Comparison
| Spec | WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) | Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive |
|---|---|---|
| Brand | Western Digital | Seagate |
| Capacity | 18TB | 18TB |
| $/GB | $0.0353 | $0.0400 |
| Price | $635.07 | $720.00 |
| 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 WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) offers better value at $0.0353//GB compared to the Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive at $0.0400//GB — that's roughly 12% less per gigabyte.
The best deal for the WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) is $635.07 at Newegg, while the Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive starts at $720.00 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 Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) and Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive product page for detailed specifications and price history.
Frequently Asked Questions
Is WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) or Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive a better deal?
As of July 2026, WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) offers better value at $0.0353//GB compared to Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive at $0.0400//GB. That is approximately 12% better value per gigabyte.
What is the price per GB of WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4)?
The WD Ultrastar DC HC550 18TB Hard Drive 3.5' Internal 512MB SATA 7200 RPM 512E SE NP3 DC HC550 0F38459 (WUH721818ALE6L4) is currently priced at $0.0353/GB ($635.07 for 18TB) at Newegg.
Where can I buy Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive for the cheapest price?
The cheapest price for the Seagate Exos X18 ST18000NM000J 18TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5' Internal Hard Drive is $720.00 at Newegg, which works out to $0.0400/GB.