Best 20TB NAS hard drives
20TB sits near the top of the capacity ladder - for when you want the most storage a single bay can hold. Every pick is CMR, NAS- or enterprise-rated and helium-sealed, ranked by measured failure rate. Budget for long rebuilds and double-parity redundancy.
| Drive | Capacity | Tech | Class | Interface | AFR | €/TB | Price | |
|---|---|---|---|---|---|---|---|---|
| 1 |
MG10ACA20TE Toshiba MG10
|
20 TB | CMR | Enterprise | SATA | 0.68% | €42.49 | €850 |
| 2 |
WD201KFGX WD Red Pro
|
20 TB | CMR | NAS-Pro | SATA | - | €58.67 | €1,173 |
| 3 |
WD202KRYZ WD Gold
|
20 TB | CMR | Enterprise | SATA | - | €45.00 | €900 |
| 4 |
WUH722020BLE6L4 WD Ultrastar DC HC560
|
20 TB | CMR | Enterprise | SATA | - | €25.90 | €518 |
| 5 |
ST20000NT001 Seagate IronWolf Pro
|
20 TB | CMR | NAS-Pro | SATA | - | - | - |
| 6 |
ST20000NM007D Seagate Exos X20
|
20 TB | CMR | Enterprise | SATA | - | - | - |
| 7 |
HAT3320-20T Synology Plus Series
|
20 TB | CMR | NAS | SATA | - | - | - |
| 8 |
HAT5320-20T Synology Enterprise Series
|
20 TB | CMR | Enterprise | SATA | - | - | - |
Ranked by measured failure rate (Backblaze AFR). $/TB uses the cheapest live price where available.
Why 20TB
Maximum capacity per bay, for dense arrays and full enclosures where adding drives isn't an option. Nearly every 20TB drive is helium-sealed, so despite the size they run cooler and draw less power than you'd expect.
The trade-offs
Two of them, and both matter. You pay a per-terabyte premium at the top of the range, so check the $/TB against a 16TB drive before committing - the density is only worth it if you're genuinely out of bays. And rebuilds are long enough that double parity stops being optional: run RAID 6 / SHR-2 with any group of large drives. Size the build first with the storage planner.
Frequently asked questions
- Do I need RAID 6 with 20TB drives?
- Strongly recommended once you run more than a few. A 20TB rebuild can take a day or more; during that time a single-parity (RAID 5) array has no protection left. Double parity (RAID 6 / SHR-2) covers a second failure.
- Are 20TB drives worth it over 16TB?
- Only if you need the density or have limited bays. The largest drives usually carry a price-per-terabyte premium - check the per-TB value before paying for the biggest tier.