RAID 5 vs RAID 6 vs RAID 10 — Storage Comparison
RAID 5, 6, and 10 are the three most common RAID configurations for enterprise server storage. Each makes different trade-offs between capacity, performance, and fault tolerance.
Quick Verdict
RAID 10 for high-IOPS workloads (databases, VMs): best performance, but 50% capacity overhead. RAID 6 for high-capacity arrays (8+ drives): dual-parity protects against the 2-week rebuild window of modern 18+ TB drives. RAID 5 only for small arrays of 3-6 drives.
Side-by-Side Spec Comparison
| Spec | RAID 5 / 6 | RAID 10 |
|---|---|---|
| Minimum Drives | RAID 5: 3; RAID 6: 4 | RAID 10: 4 |
| Drive Failures Tolerated | RAID 5: 1; RAID 6: 2 | 2 (in different mirror pairs) |
| Capacity Efficiency | RAID 5: (n-1)/n; RAID 6: (n-2)/n | 50% |
| Read IOPS | Good (parallel reads) | Excellent (parallel reads + mirrors) |
| Write IOPS | Poor (parity calculation) | Excellent (no parity) |
| Rebuild Time (18 TB drive) | 1-2 weeks (parity recalculation) | 1-2 days (mirror copy only) |
| Typical Use | Capacity-focused storage (archive, backup) | Performance-focused storage (DB, VM) |
Green-highlighted cells indicate the winner for that spec.
Frequently Asked Questions
Should I use RAID 5 in 2026?
Avoid for arrays > 6 drives or drives > 8 TB. Modern 18-22 TB drives have rebuild times approaching 2 weeks at RAID 5 — during which a second drive failure causes total data loss. Use RAID 6 (dual parity) for larger arrays.
When should I use RAID 10 vs RAID 6?
RAID 10 for OLTP databases, VM datastores, any high-IOPS workload — 4-8× better random write performance. RAID 6 for archival/backup/file storage where capacity efficiency matters more than performance.
Does software RAID work as well as hardware RAID?
For RAID 10 — yes, software RAID (mdadm on Linux, Storage Spaces on Windows) performs comparably to hardware RAID. For RAID 5/6 — hardware RAID is faster because of dedicated parity calculation ASIC. ZFS uses software RAID-Z with excellent performance via in-RAM checksums.
Our Recommendation
RAID 10 for high-IOPS production. RAID 6 for capacity-focused storage and any large array. RAID 5 only for small (3-6 drive), low-capacity arrays where the rebuild risk is manageable.
Need help deciding?
Email sales@prodisknetwork.com with your specific requirements. Our team will match you to the right product based on your workload, budget, and existing infrastructure.