NAS pSEO Landing
Brand Focus · Unraid
Estimate usable capacity, fault tolerance, and efficiency for Unraid NAS users using 4x 8TB in RAID 10.
Raw Capacity
32.00 TB
Usable Capacity
14.40 TB
Fault Tolerance
1 drive per mirror pair*
Efficiency
50.0%
Excellent random I/O and rebuild behavior; capacity is typically 50% of raw. This scenario applies a 10% filesystem reserve.
Run Interactive Calculator →| Mode | Usable | Tolerance | Efficiency |
|---|---|---|---|
| RAID 5 | 21.60 TB | 1 drive | 75.0% |
| RAID 6 | 14.40 TB | 2 drives | 50.0% |
| RAID 10 | 14.40 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 21.60 TB | 1 drive | 75.0% |
| RAID-Z2 | 14.40 TB | 2 drives | 50.0% |
Unraid users often optimize for incremental growth and flexible disk replacement, where parity planning and usable capacity targets evolve over time rather than all at once.
Dedicated parity disk(s) protecting data disks in the Unraid array model.
Fast SSD/NVMe pool used for writes and application workloads.
Scheduled process that migrates data between cache and array tiers.
For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.
No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.
For Unraid users, this NAS planning scenario estimates 14.40 TB usable after a 10% reserve from 32.00 TB raw.
Keeping free space improves filesystem behavior for snapshots, metadata, and write performance. Full arrays often perform worse and rebuild more slowly.