Seagate IronWolf Pro ST4000NT001 4TB 7200 RPM 256MB SATA 3.5" internal hard drive

Built for Multi-Bay NAS

The Seagate IronWolf Pro ST4000NT001 is a 4TB 3.5-inch internal hard drive designed for commercial and enterprise NAS systems. It spins at 7200 RPM with a 256MB cache and uses CMR recording technology. The SATA 6.0Gb/s interface connects directly to standard drive bays. AgileArray firmware adds dual-plane balancing and time-limited error recovery for consistent RAID performance in multi-bay enclosures. This drive is built for 24x7 operation in always-on environments.

Suits RAID Arrays Not Single Desktop PCs

This drive targets administrators running multi-user, multi-bay NAS appliances that demand sustained throughput and RAID optimisation. The firmware and vibration tuning are calibrated for dense chassis, not standalone workstations. Buyers who need a quiet, low-power drive for a single-bay home PC or external enclosure should look elsewhere. The enterprise feature set adds cost and acoustic output that a typical desktop workload does not justify.

Four Terabytes With 256MB Cache Headroom

The 4TB capacity handles growing media libraries, virtualisation datastores and backup repositories across multiple bays. The 256MB cache absorbs bursty write streams common in RAID rebuilds and concurrent user access. In heavy sustained write scenarios the 7200 RPM platters eventually become the bottleneck, limiting peak throughput compared to solid-state alternatives. For workloads exceeding this capacity or speed tier, a higher-capacity IronWolf Pro model or SSD tier is required.