See Which Internal Drive Is Inside Each External
Which internal drive is inside each external, by family and capacity, kept current
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This is the current external-to-internal shucking list: what drive typically ships inside each WD Elements, easystore, My Book and Seagate Expansion, by capacity, with recording type (CMR or SMR) and a confidence rating. The mapping is community-sourced and kept current, unlike the widely-shared 2023 lists. The same drive sits inside the US and Canadian units, so this list is the same in both markets; use the tracker for live pricing.
How the list works
Amazon rotates which internal drive ships in a given external, so no list is guaranteed. High confidence means the family and capacity almost always yield the listed CMR white-label drive; low confidence means it varies or can be SMR. WD Elements and easystore of 8TB and up are nearly always CMR white-label (WD Red Plus or Ultrastar class); Seagate Expansion Desktop of 12TB and up is Exos or IronWolf-class CMR.
The safest shucks are the 12TB and larger units. Below 8TB, both WD and Seagate externals can contain SMR drives that rebuild slowly and are poor for RAID. Always confirm the exact model with CrystalDiskInfo after shucking.
WD Elements
| Capacity | Typical internal drive | Recording | Confidence | Notes |
|---|---|---|---|---|
| 22 TB | WD Ultrastar DC HC570 (WUH722222) class, CMR | CMR | high | Air or helium Ultrastar-class. 3.3V pin workaround often needed. |
| 20 TB | WD Ultrastar DC HC560 / white-label EDGZ, CMR | CMR | high | Reliable high-capacity shuck. Tape pin 3 or use a Molex-only PSU. |
| 18 TB | WD White-label WD180EDGZ (Ultrastar/Red Pro class), CMR | CMR | high | One of the best value shucks. 3.3V pin often applies. |
| 16 TB | WD White-label WD160EDGZ / EMFZ (Red Pro class), CMR | CMR | high | Common CMR shuck, RAID-safe after SMART check. |
| 14 TB | WD White-label WD140EDFZ (Red Plus/Ultrastar class), CMR | CMR | high | Reliable CMR. 3.3V pin often applies. |
| 12 TB | WD White-label WD120EMFZ / EMAZ, CMR | CMR | high | Classic shuck target, CMR white-label. |
| 10 TB | WD White-label WD100EMAZ (Red/Ultrastar class), CMR | CMR | medium | Usually CMR; verify model after shucking. |
| 8 TB | WD White-label WD80EMAZ / EAZZ, CMR | CMR | medium | 8TB is usually CMR but a few EAZZ variants vary; SMART-check. |
| 6 TB | WD Blue-class; can be SMR | often SMR | low | Small Elements can be SMR. Not recommended for RAID. |
WD easystore
| Capacity | Typical internal drive | Recording | Confidence | Notes |
|---|---|---|---|---|
| 16 TB | WD White-label / WD Red-class (WD160EDFZ), CMR | CMR | high | Best Buy exclusive; frequently the best sale-price WD shuck. |
| 14 TB | WD White-label WD140EDFZ (Red Plus class), CMR | CMR | high | Often red-label WD Red inside; watch Best Buy sales. |
| 12 TB | WD White-label WD120EMFZ, CMR | CMR | high | CMR. Sale prices can beat Elements. |
| 8 TB | WD White-label WD80EMAZ (sometimes red-label WD Red), CMR | CMR | medium | Occasionally a genuine red-label WD Red; luck of the draw. |
WD My Book
| Capacity | Typical internal drive | Recording | Confidence | Notes |
|---|---|---|---|---|
| 18 TB | WD White-label WD180EDGZ (Ultrastar class), CMR | CMR | medium | Enclosure does hardware encryption - shuck the bare drive, do not trust the bridge. |
| 14 TB | WD White-label WD140EDFZ, CMR | CMR | medium | Same internals as Elements; encrypted bridge only matters if left in enclosure. |
| 12 TB | WD White-label WD120EMFZ, CMR | CMR | medium | CMR white-label. Shuck to bypass the encrypting bridge. |
Seagate Expansion
| Capacity | Typical internal drive | Recording | Confidence | Notes |
|---|---|---|---|---|
| 20 TB | Seagate Exos / IronWolf-class (ST20000NM), CMR | CMR | high | High-capacity Expansion is Exos-class CMR. No 3.3V pin issue on Seagate. |
| 18 TB | Seagate Exos / BarraCuda Pro-class (ST18000NM), CMR | CMR | high | Exos-class CMR. Seagate externals rarely need the pin tape. |
| 16 TB | Seagate Exos / IronWolf-class (ST16000NM), CMR | CMR | high | CMR datacenter-class. Strong RAID shuck. |
| 12 TB | Seagate BarraCuda / IronWolf-class (ST12000), CMR | CMR | medium | Usually CMR at 12TB; SMART-check the model after shucking. |
| 10 TB | Seagate BarraCuda-class (ST10000), CMR | CMR | medium | Typically CMR; verify model. |
| 8 TB | Seagate BarraCuda ST8000DM004 - often SMR | often SMR | low | 8TB Expansion is frequently SMR (DM004). Fine for cold storage, not RAID. |
| 6 TB | Seagate BarraCuda-class; can be SMR | often SMR | low | Small units are often SMR. Not recommended for RAID rebuilds. |
Mappings are typical, not guaranteed. Amazon rotates which internal ships in a given external, so the exact model varies by batch and region. High confidence means the family and capacity almost always yield the listed CMR white-label; low confidence means it can be SMR or varies. Always confirm the model with CrystalDiskInfo and run a full surface test before using a shucked drive in a RAID array. Shucking voids the external's warranty.
Frequently asked questions
Which external has the best drive to shuck?
The 14TB to 20TB WD Elements and easystore almost always contain CMR white-label drives in the WD Red Plus or Ultrastar class, and the 16TB and larger Seagate Expansion holds Exos-class CMR. These high-capacity units give both the best price per terabyte and the most reliable CMR result.
How do I know if a shucked drive is CMR or SMR?
Check the model number after shucking with CrystalDiskInfo, then look it up. As a rule, WD Elements and easystore 8TB and up are CMR, Seagate Expansion 12TB and up are CMR, and most 6-8TB externals risk being SMR. This list gives the typical result per capacity.
Is the drive inside the same in the US and Canada?
Yes. Amazon.com and Amazon.ca ship the same external SKUs with the same internal drives, so this mapping applies to both markets. Only the price differs, which is why the live tracker shows USD on the US site and CAD on the Canadian site.
What tools do I need to check a shucked drive?
CrystalDiskInfo to read the model and SMART health, and a full-surface test such as the extended SMART self-test or badblocks before you trust the drive with data. For WD drives, keep Kapton tape handy for the 3.3V pin fix.