Side-by-side spec and price comparison. Live data from Amazon US.
Seagate IronWolf 4TB NAS offers the best value at $47.50/TB. Available new with manufacturer warranty.
Seagate IronWolf offers better value at $47.50/TB vs $76.94/TB - a 38% 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 IronWolf carries a longer 3-year warranty vs unknown years for WD Ultrastar. Longer warranty typically correlates with manufacturer confidence in reliability.
Seagate IronWolf is the better fit for NAS storage. It uses CMR recording which is safe for all RAID levels. SATA interface is compatible with all NAS platforms including Synology, QNAP and TrueNAS.