DatacenterDisk

Seagate 16TB vs WD Ultrastar

Side-by-side spec and price comparison. Live data from Amazon US.

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Our Recommendation
👑
Seagate 16TB SAS 12G 7.2K

Seagate 16TB SAS 12G 7.2K balances price ($40.28/TB), warranty (5 years), and 550TB/yr workload rating for the best overall value.

Best $/TB: WD
Best Warranty: Seagate
Best for RAID: Seagate
Full Specification Comparison
Spec
Seagate
16TB SAS 12G 7.2K
$40.28/TB
WD
Ultrastar 16TB SAS WUH721816AL5205
$32.81/TB
Brand
Seagate
WD
Model
16TB SAS 12G 7.2K
Ultrastar 16TB SAS WUH721816AL5205
Series
Exos X
Ultrastar HC550
Part Number
ST16000NM002G
WUH721816AL5205
$/TB
$40.28
👑$32.81
Price
$644.44
$525.00
Condition
New
Refurb
Capacity
16TB
16TB
Interface
SAS-12G
SAS-12G
Form Factor
3.5"
3.5"
Drive Type
HDD
HDD
Recording Tech
CMR
CMR
RPM
7,200
N/A (SSD)
Cache
—
—
Sector Size
512e
512e
Workload Rating
550TB/yr
—
DWPD
N/A
N/A
Warranty
5 years
—
Workload Tier
nearline
nearline
In Stock
✓ In Stock
✓ In Stock
Buy
Buy on Amazon →
Buy on Amazon →
Workload Fit
Workload
Seagate
WD
NAS Storage
●●
●●
Backup Target
●●●
●●●
OLTP Database
●
●
Cold Archive
●●●
●●●
Virtualization
●
●
AI/ML Storage
●●
●●
Buying Recommendation
Choose Seagate 16TB SAS 12G 7.2K if:
  • ✓ You need 5-year warranty coverage for production
  • ✓ You're building a RAID array and need guaranteed CMR compatibility
  • ✓ Your server runs 24/7 under heavy sustained load
  • ✓ You need new-with-warranty for compliance or budgeting
Buy Seagate →
Choose WD Ultrastar 16TB SAS WUH721816AL5205 if:
  • ✓ You need maximum storage per dollar
  • ✓ You're comfortable with datacenter refurb to maximize savings
  • ✓ You need high-density storage for bulk/archive workloads
Buy WD →

Frequently Asked Questions

WD Ultrastar offers better value at $32.81/TB vs $40.28/TB - a 19% price difference. Factor in warranty length and workload rating when the price gap is small.

Mixing drives of different models in RAID is not recommended even if capacities match. Different firmware, error handling and seek patterns can cause rebuild issues. Use identical drives within the same RAID group for reliable operation.

Seagate 16TB carries a longer 5-year warranty vs unknown years for WD Ultrastar. Longer warranty typically correlates with manufacturer confidence in reliability.

Seagate 16TB is the better fit for NAS storage. It uses CMR recording which is safe for all RAID levels. SAS interface requires a SAS HBA or SAS-capable NAS.

Seagate 16TB vs WD Ultrastar - Comparison | DatacenterDisk