Best 20 TB Hard Drives
20 TB drives sit at the high end of mainstream capacity, offering maximum density for builds where every bay slot counts. These are almost exclusively helium-sealed enterprise or NAS models, delivering excellent sustained throughput and power efficiency per terabyte. If you are building dense storage (whether a JBOD shelf, a high-capacity NAS, or a Plex archive) 20 TB drives let you pack more usable storage into fewer slots.
Why 20 TB?
20 TB drives deliver roughly 11% more capacity than 18 TB at a modest price premium. But check the per-TB cost carefully, as 18 TB sometimes wins on value. The sweet spot is when 20 TB models are on sale or when bay slots are your limiting factor. Four 20 TB drives in RAID 5 give you ~60 TB usable.
Prices updated daily from Amazon.com. All links go directly to the retailer. Details.
Bottom line: the lowest price-per-TB pick on this page right now is the Avolusion M5 Series 20TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (Renewed), 20 TB used, at $539.99 ($27.00/TB) on Amazon.com. Check the current price.
Best Value 20 TB Drives
All new 20 TB hard drives ranked by price per terabyte across brands and product lines.
OSENTRiX BX100 20TB USB 3.2 Gen 2 USB-C External Hard Drive for Windows or MacOS Desktop PC/Laptop
Seagate One Touch 20TB External Hard Drive Desktop HDD - USB-C Compatible with Most Windows and macOS, Rescue Recovery (STNB20000400)
MDD MAXDIGITALDATA 20TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5'' Internal Hard Drive (for NAS, Network Storage) - 5 Years Warranty
Seagate 20TB Expansion Desktop Hard Drive | MicroB to USB-C (STNP20000400) | New Generation of High-capacity HDD storage for backup & archive, Windows & macOS compatible. 1-Year Warranty + 1-Year Rescue
BUFFALO Replacement Spare Hard Drive 20TB NAS-Grade for TeraStation 2/4/8 Bay (OP-HD20.0N)
Avolusion PRO-G1 Series 20TB USB 3.2 Gen 2 (10Gbps) USB-C External Hard Drive for Windows or MacOS Desktop PC/Laptop (Silver)
Genuine NT45N 20TB 7.2K SAS 3.5 12Gb/s HDD 14G 15G Original
SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.
Genuine 20TB 7.2K SAS 3.5 12Gb/s HDD 512e Original
SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.
Enterprise 20 TB Drives
Exos and Ultrastar 20 TB models for datacenter and server workloads. Maximum density with 24/7 endurance ratings.
Seagate Exos X24 20TB Enterprise Internal Hard Drive HDD - 12GB/s SAS 7200RPM 2.5M MTBF (ST20000NM002H)
SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.
Seagate Exos X20 ST20000NM000D 20 TB Hard Drive - Internal - SATA (SATA/600) - Conventional Magnetic Recording (CMR) Method - Storage System, Video Surveillance System Device Supported - 7200rpm - 285
WD Ultrastar DC HC560 WUH722020BL5204 20 TB Hard Drive - 3.5" Internal - SAS (12Gb/s SAS) - 7200rpm - 4Kn Format - 5 Year Warranty
SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.
NAS 20 TB Drives
IronWolf and WD Red 20 TB models for high-capacity NAS builds. NAS firmware with vibration tolerance and RAID-optimised error recovery.
Seagate IronWolf Pro, 20 TB, Enterprise NAS Internal HDD –CMR 3.5 Inch, SATA 6 Gb/s, 7,200 RPM, 256 MB Cache for RAID Network Attached Storage (ST20000NT001)
Western Digital 20TB WD Red Pro NAS Internal Hard Drive HDD - 7200 RPM, SATA 6 Gb/s, CMR, 512 MB Cache, 3.5" - WD202KFGX
Western Digital 20TB WD Red Pro NAS Internal Hard Drive HDD - 7200 RPM, SATA 6 Gb/s, CMR, 512 MB Cache, 3.5" - WD201KFGX
Seagate IronWolf Pro SATA III 3.5" Internal NAS Hard Drive, 7200 RPM -
Refurbished 20 TB Drives
Recertified 20 TB enterprise pulls at significant discounts. High-density storage for homelabs, archives, and Plex libraries on a budget.
Avolusion M5 Series 20TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (Renewed)
Western Digital WD Ultrastar 20TB Internal Hard Drive WD200EDGZ 3.5 Inch HDD SATA 6Gb/s 7200RPM 512MB Cache (Renewed)
WD 20TB Elements Desktop External Hard Drive, USB 3.0 drive for plug-and-play storage - WDBWLG0200HBK-NESN
Avolusion PRO-Z Series 20TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (White) (Renewed)
Western Digital WD Ultrastar 20TB Internal Hard Drive WD200EDGZ 3.5 Inch HDD SATA 6Gb/s 7200RPM 512MB Cache (Renewed)
Western Digital Ultrastar DC HC560 WUH722020ALE604 0F38761 20TB 7.2K RPM CMR SATA 6Gb/s 512e 3.5in Enterprise HDD
Avolusion PRO-T5 Series USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (White) - 2 Year Warranty (20TB) (Renewed)
MDD MAXDIGITALDATA MDD 20TB 7200 RPM 256MB Cache 3.5-inch Internal Enterprise Hard Drive - 5 Years Warranty (Renewed)
Frequently Asked Questions
Why choose a 20 TB drive?
20 TB gives you roughly 11% more capacity than 18 TB per bay, which matters most when bay slots are your limiting factor — a dense JBOD, a full NAS, or a large Plex archive. These are almost all helium-sealed enterprise or NAS models with strong sustained throughput and good power efficiency per terabyte. Four 20 TB drives in RAID 5 give about 60 TB usable.
Is 20 TB better value than 18 TB?
Check the per-terabyte cost before assuming either way. In our 2026-08-20 snapshot 20 TB ($25.00/TB) had dropped below 18 TB ($27.72/TB), so 20 TB won on both value and density per bay. The 2026 shortage keeps these tiers moving, so compare the live $/TB on this page and buy 20 TB when it is on sale or when slots are scarce.
Are 20 TB drives CMR?
Yes — 20 TB drives are helium-sealed enterprise and NAS models using CMR, safe for RAID and ZFS arrays. There are no mainstream SMR drives at this capacity.
Are 20 TB drives reliable enough to trust?
They are enterprise-class drives rated for 24/7 operation, high workloads, and 2M+ hour MTBF, so reliability is strong. But no single drive is a backup strategy — at this capacity a rebuild moves a lot of data, so run 20 TB drives in a redundant array (RAID or ZFS) and keep a separate backup copy.
New or refurbished at 20 TB?
New 20 TB drives include a 5-year enterprise warranty; refurbished pulls at this capacity are rarer and the discount is often thin (in our August 2026 data used 20 TB saved little over new). Compare the current new and used $/TB on this page — at 20 TB, new is frequently the better all-in value once warranty is priced in.
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