NAS planning example
Compare usable TB, parity cost, and fault tolerance between RAID 6 and RAID 5 for NAS and homelab arrays.
Planning route
Use this worked example as a numeric starting point, then validate the RAID choice, capacity reserve, hardware plan, and backup path.
Editorial method
The capacity model makes drive count, drive size, RAID layout, and reserve visible. It is a planning aid: it does not predict exact performance, rebuild duration, hardware compatibility, or the probability of data loss for a specific system.
Last reviewed: July 10, 2026. Product links remain neutral category searches until a partner relationship and page-level disclosure are in place.
This page compares RAID 6 and RAID 5 on identical hardware assumptions to help homelab builders choose between capacity efficiency and fault tolerance.
| Drives | RAID 6 | RAID 5 | Delta |
|---|---|---|---|
| 4x 8TB | 14.40 TB | 21.60 TB | -7.20 TB |
| 6x 8TB | 28.80 TB | 36.00 TB | -7.20 TB |
| 8x 8TB | 43.20 TB | 50.40 TB | -7.20 TB |
| 10x 8TB | 57.60 TB | 64.80 TB | -7.20 TB |
| 12x 8TB | 72.00 TB | 79.20 TB | -7.20 TB |
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FAQ
Rebuild behavior depends on array width, disk size, and workload pressure. This page focuses on capacity and tolerance; benchmark your actual platform before final choice.
Choose based on your risk tolerance, rebuild window, and performance profile. Higher parity usually lowers capacity but improves resilience.
This NAS planning scenario compares both modes at fixed drive sizes so you can see usable capacity differences before buying disks.
The better option is the one that keeps acceptable usable capacity while preserving safety margins during future disk expansions.