NAS pSEO Landing
Brand Focus · Unraid
Compare usable TB, parity, and failure tolerance between RAID-Z3 and RAID-Z2 for Unraid NAS users.
This page compares RAID-Z3 and RAID-Z2 on identical hardware assumptions to help homelab builders choose between capacity efficiency and fault tolerance.
| Drives | RAID-Z3 | RAID-Z2 | Delta |
|---|---|---|---|
| 4x 8TB | N/A | 14.40 TB | N/A |
| 6x 8TB | 21.60 TB | 28.80 TB | -7.20 TB |
| 8x 8TB | 36.00 TB | 43.20 TB | -7.20 TB |
| 10x 8TB | 50.40 TB | 57.60 TB | -7.20 TB |
| 12x 8TB | 64.80 TB | 72.00 TB | -7.20 TB |
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 Unraid users, this NAS planning scenario compares both modes at fixed drive sizes so you can see usable capacity differences before buying disks.
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.
Yes. Similar usable TB does not imply similar failure tolerance or rebuild exposure. Capacity and resiliency should be evaluated together.
The better option is the one that keeps acceptable usable capacity while preserving safety margins during future disk expansions.