Side-by-side spec and price comparison. Live data from Amazon US.
HGST Ultrastar He8 8TB SAS 12G balances price ($36.13/TB), warranty (5 years), and enterprise reliability for the best overall value.
HP 834031-B21 offers better value at $33.13/TB vs $36.13/TB - a 8% 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.
HGST Ultrastar carries a longer 5-year warranty vs unknown years for HP 834031-B21. Longer warranty typically correlates with manufacturer confidence in reliability.
HGST Ultrastar 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.