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5x 12TB RAID 5 NAS Calculator | Usable TB

Estimate usable TB, parity overhead, and fault tolerance for 5x 12TB in RAID 5. Includes reserve planning for NAS and homelab arrays.

Capacity Snapshot

Raw Capacity

60.00 TB

Usable Capacity

43.20 TB

Fault Tolerance

1 drive

Efficiency

80.0%

Balanced capacity and redundancy, but rebuild stress can be high on large disks. This scenario applies a 10% filesystem reserve.

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Alternative Mode Comparison

Mode Usable Tolerance Efficiency
RAID 5 43.20 TB 1 drive 80.0%
RAID 6 32.40 TB 2 drives 60.0%
RAID 10 N/A N/A N/A
RAID-Z1 43.20 TB 1 drive 80.0%
RAID-Z2 32.40 TB 2 drives 60.0%

NAS Cluster Guides

NAS Hub RAID Level Compare RAID Capacity Matrix Planning Quick Sheet RAID Selector NAS FAQ

Related Long-Tail Calculators

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Sequential Long-Tail Navigation

← Previous: 5x 12TB RAID 1 NAS Calculator | Usable TB Next: 5x 12TB RAID 6 NAS Calculator | Usable TB →

FAQ

How many disk failures can RAID 5 tolerate in this setup?

This setup can tolerate 1 drive. Real-world survivability depends on mirror placement, rebuild stress, and drive health.

Why include a 10% reserve when planning NAS storage headroom?

Keeping free space improves filesystem behavior for snapshots, metadata, and write performance. Full arrays often perform worse and rebuild more slowly.

Should I optimize this 5-drive plan for available space or resiliency first?

For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.

Can this calculator replace real-world benchmark and rebuild testing?

No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.