The cheapest 5TB external in stock right now is the WD Elements 5TB Portable HDD at $40.39/TB ($202 total), a portable hdd unit. 5TB is the mainstream external capacity, where portable and desktop units overlap and the widest choice exists. It is large enough to be a real backup target for one machine and small enough to still be available in a bus-powered portable form. No maker publishes which drive is inside an external enclosure, so the table below says so rather than guessing.
13 in-stock listings · desktop, portable and SSD
Best cost per terabyte here right now: WD Elements 5TB Portable HDD at $40.39/TB ($202 for 5TB, portable hdd, used listing). The drive inside it is not disclosed by the maker.
| Model | Capacity | Family | Interface | Inside | Warranty | Condition | $/TB | Price | |
|---|---|---|---|---|---|---|---|---|---|
| WD Elements 5TB Portable HDD | 5TB | Portable HDD | USB 3.2 GEN 1 | NOT DISCLOSED | — | USED | $40.39 | $202 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | USED | $42.63 | $213 | Buy |
| LaCie Rugged 5TB Portable HDD | 5TB | Portable HDD | USB | NOT DISCLOSED | — | NEW | $43.50 | $217 | Buy |
| WD Elements 5TB Portable HDD | 5TB | Portable HDD | USB 3.2 GEN 1 | NOT DISCLOSED | — | NEW | $43.99 | $220 | Buy |
| Seagate One Touch 5TB Portable HDD | 5TB | Portable HDD | USB 3.0 | NOT DISCLOSED | — | NEW | $45.64 | $228 | Buy |
| LaCie Rugged 5TB Portable HDD | 5TB | Portable HDD | USB-C | NOT DISCLOSED | — | NEW | $48.00 | $240 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | USED | $48.71 | $244 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | NEW | $53.00 | $265 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | NEW | $56.00 | $280 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | NEW | $56.86 | $284 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | NEW | $57.00 | $285 | Buy |
| WD My Passport 5TB Portable HDD | 5TB | Portable HDD | USB 3.1 | NOT DISCLOSED | — | NEW | $59.00 | $295 | Buy |
| Seagate One Touch 5TB Portable HDD | 5TB | Portable HDD | USB | NOT DISCLOSED | — | NEW | $59.99 | $300 | Buy |
“Inside” is not disclosed by any maker for these products and the contents vary by batch, so we state that rather than guessing — see what the community has found by opening them. Warranty shows a dash because the makers' warranty pages did not resolve through our source-verification path; read the term on the maker's page for the exact model. Interface is the maker's own specification string, not a speed measurement.
There is no bare internal SATA drive in stock at 5TB to compare against, so this arithmetic cannot be run at this capacity. That is usually because the bare-drive market does not sell this size — 5TB is a 2.5-inch format that appears in externals and laptops rather than in desktop drive bays. Shucking is not a question here: there is no bare equivalent to buy instead. The shucking guide covers the mechanics for the capacities where the comparison does apply.
5TB is the mainstream external capacity, where portable and desktop units overlap and the widest choice exists. It is large enough to be a real backup target for one machine and small enough to still be available in a bus-powered portable form.
At 5TB the market currently offers bus-powered portables from $40.39/TB and nothing else. A single family at a capacity usually means the others are either physically unable to reach it or priced out of it, and the table above shows which.
The question worth asking at this size is whether one capacity up costs meaningfully more. Cost per terabyte does not scale linearly, so the next rung is frequently cheaper per terabyte and occasionally barely more in absolute terms. For a backup target in particular, buying short is a false economy: versioned backups keep history, history grows, and a target that fills stops protecting you.
The other half of the decision is what the drive plugs into. Externals connect over USB and that is the whole interface story; there is no path to putting one in a bay without opening it, which is the subject of the shuck arithmetic above. If the storage is destined for a machine's internal bays or an array, our 5TB bare drives page covers the drives whose specifications the maker actually publishes.
The split between the two mechanical families is physical rather than commercial. Desktop externals are 3.5-inch drives with their own mains adapter; portable externals are 2.5-inch drives running on USB power alone. The 2.5-inch format tops out at considerably lower capacities than the 3.5-inch format, and that ceiling is a hardware limit rather than a marketing decision.
At 5TB the market is portable-heavy in our tables right now, which is normal at the smaller capacities where a 3.5-inch desktop unit would be an odd product to build.
A practical note that catches people out: desktop externals are not designed to be moved while running, and the mechanical failure mode for a spinning drive that gets knocked is abrupt. If the drive is going to travel at all, buy the portable and accept the higher rate per terabyte, because the alternative is a cheap drive and a bad afternoon.
There is no shuck arithmetic to run at 5TB, and the block above says so rather than leaving a gap. No bare internal SATA drive is in stock at this capacity for us to compare against, which at this size is usually because the bare-drive market does not sell it: 5TB is a 2.5-inch format that reaches consumers inside externals and laptops rather than as a drive you buy for a desktop bay.
That makes the decision simpler rather than harder. With no bare equivalent to buy instead, opening a 5TB external gets you a drive you could not have bought on its own — which is occasionally the point, but it is not a saving, and it still costs you the warranty.
Even a real saving comes with three costs. You do not know which drive is inside before opening it and the contents vary by batch. Opening ends the warranty on the external. And some units use a 3.3V power-disable pin that stops the drive spinning up on a normal desktop power connector, which is fixable with tape or an adapter but is an unwelcome discovery mid-build. Our shucking guide covers all three properly.
At this capacity the fake-capacity risk is lower than at the bulk sizes, because the fraud economics work best where the advertised number is large. It is not zero, and the same brand rule applies: a capacity from a name with no history outside the listing is the signal to walk away.
The WD Elements 5TB Portable HDD at $40.39 per terabyte, $201.95 in total, from a used listing. That is computed when this page loads from our tracking of in-stock Amazon US listings and it changes — out-of-stock drives are excluded entirely rather than shown at a last-known price.
Yes — there is a bus-powered portable at 5TB in stock right now, alongside no desktop option. Portables are 2.5-inch drives running on USB power alone, so they cost more per terabyte than a mains-powered desktop unit of the same size.
There is no bare internal SATA drive in stock at 5TB to compare against, so there is no saving to calculate. At this size the bare-drive market largely does not sell the format, which means opening an external gets you a drive you could not otherwise buy rather than a cheaper version of one you could. You would still be giving up the warranty and still not know which drive is inside until the case is open.
No maker publishes it, and the contents vary between production batches of the same model number. That is why every row above reads "not disclosed". Our shucking guide carries what the community reports finding, framed as batch-varying observations rather than specifications, which is what they are.
Treat it with suspicion and verify it. Fake-capacity drives report a size they do not have and only fail once you write past the real capacity, which is usually after the return window. Our filters reject anything under $8/TB and any unfamiliar brand above 2TB, but if you buy outside our tables, write a full drive of real data and read it back.
The rule worth applying is that a backup target should be comfortably larger than the data it protects, because versioned backup systems keep history and history grows. Time Machine, File History and their equivalents all behave badly once the target fills. If 5TB is roughly the size of what you are protecting, buy a rung up — it is usually cheaper per terabyte anyway. Our backup guidance covers sizing and the rotation discipline.
Specification claims on this page were checked against the pages below on 4 August 2026. Where a widely-repeated figure did not survive that check, we report what the source says now and say so in the text rather than repeating the familiar number.