NAS pSEO Landing
Region Focus · US
Estimate usable capacity, fault tolerance, and efficiency for US homelab buyers using 4x 8TB in RAID 5.
Raw Capacity
32.00 TB
Usable Capacity
21.60 TB
Fault Tolerance
1 drive
Efficiency
75.0%
Balanced capacity and redundancy, but rebuild stress can be high on large disks. 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% |
US buyers often evaluate frequent pricing swings and promo cycles. Capacity planning should account for staged purchases instead of one-time all-disk upgrades.
Planning metric that compares real usable capacity after reserve and parity.
Seasonal pricing period used for phased drive purchasing strategies.
Keeping free space improves filesystem behavior for snapshots, metadata, and write performance. Full arrays often perform worse and rebuild more slowly.
No. Use this page for pre-purchase sizing, then validate with workload benchmarks, SMART health policy, and a tested restore plan.
This setup can tolerate 1 drive. Real-world survivability depends on mirror placement, rebuild stress, and drive health.
For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.