NAS pSEO Landing
Region Focus · US
Estimate usable TB, parity, and fault tolerance for US homelab buyers using 4x 20TB in RAID 10.
Raw Capacity
80.00 TB
Usable Capacity
36.00 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 | 54.00 TB | 1 drive | 75.0% |
| RAID 6 | 36.00 TB | 2 drives | 50.0% |
| RAID 10 | 36.00 TB | 1 drive per mirror pair* | 50.0% |
| RAID-Z1 | 54.00 TB | 1 drive | 75.0% |
| RAID-Z2 | 36.00 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.
It can be practical, but larger drives increase rebuild windows. Validate parity choice and backup policy before committing to the final layout.
For US homelab buyers, this NAS planning scenario estimates 36.00 TB usable after a 10% reserve from 80.00 TB raw.
For long-lived NAS pools, resiliency first is usually safer. Capacity can be expanded later, while a risky parity choice can force migration sooner.
This setup can tolerate 1 drive per mirror pair*. Real-world survivability depends on mirror placement, rebuild stress, and drive health.