An external SSD earns its place when a small carry size or a short copying window matters. A portable hard drive may offer the capacity the copy needs in a larger body. The useful comparison starts with the files you must keep, then the space and time available to carry or copy them.

Below, a 4TB Samsung T7 Shield and a 5TB Seagate Expansion make those trade-offs concrete. They are reference models, not a best-drives ranking: you may need a different capacity, or already have an authorized drive that does the job. Work-data rules can also require a managed service instead.

Before comparing devices, name the failure you need to recover from. A deleted project folder, a failed computer, a lost travel drive, and loss of access to an employer account can require different copies and different owners. If the important file exists only on the computer and one attached drive, losing access to both can still end the recovery path.

Build the route from the files to an independent copy and back again

Name the recovery job

Record the source, the folders or systems in scope, and how current the recovered copy must be.

Place authorized copies

The independent destination might be an organization-managed service or another approved backup location; policy decides.

Prove the return path

A successful copy operation is not yet a successful restore. Test the route before relying on it.

The first backup question is what you would need to get back

Start with a small recovery inventory. It should describe the work, not the storage device:

  • Source: where the authoritative files live now, including any application or account needed to read them.
  • Scope: which folders, project assets, mailboxes, or other data are actually part of this plan.
  • Recovery point: how old a restored copy may be before it is no longer useful.
  • Recovery place: which computer, account, or application could receive the files if the normal setup were unavailable.
  • Recovery owner: whether you, an employer, a client, or a service administrator is responsible for the restore.

This inventory reveals whether you need a carried working copy, a retained backup, or both. A carried copy helps when the same permitted files must move between locations. A retained copy helps when the source is lost, damaged, changed, or inaccessible. One device may participate in both jobs, but the jobs should not be treated as interchangeable.

Capacity follows from that inventory. Measure the current in-scope data, then allow for the versions and growth the real retention plan requires. Do not choose a capacity from one folder today if the backup job includes other folders or historical versions tomorrow. The backup software or managed service documentation should explain whether its capacity figure includes version history, system data, compression, or deleted-file retention.

A personal drive is not automatically an approved work location

Work-data rules come before the SSD-versus-HDD decision. An employer or client may require organization-managed storage, prohibit removable media, restrict where data may be taken, or specify encryption, retention, and deletion controls. A personal drive that is technically compatible can still be the wrong destination.

Check the applicable policy or ask the person responsible for the data these questions:

  1. May these files be copied to personally owned removable storage?
  2. Which approved service or device must hold the backup?
  3. What encryption and access controls are required, and who retains the recovery key?
  4. How long must versions be kept, and who may delete them?
  5. Who performs a restore when the normal computer or account is unavailable?

CISA’s device-data guidance recommends backing up data to a secure external drive or a properly vetted cloud service and protecting removable media with encryption. That is useful data-protection context, but it does not authorize a personal drive for a particular workplace or identify which cloud service meets an organization’s rules.

If policy assigns an approved managed service and recovery owner, that route is the starting point. An external drive may still be allowed as an additional copy or transfer device, but only within those rules. If policy is unclear, pause the purchase and resolve the destination first.

A smaller 4TB SSD or a larger 5TB hard drive?

These examples separate capacity from the space a drive takes in your bag. The figures come from Samsung’s T7 Shield data sheet (PDF) and Seagate’s Expansion Portable data sheet (PDF), read on October 17, 2026. The Seagate model here is STKM5000400, not an interchangeable claim about every Expansion drive.

Published attribute Samsung T7 Shield 4TB Seagate Expansion Portable 5TB
Model MU-PE4T0S/AM STKM5000400
Nominal capacity 4TB 5TB
Body dimensions 59 × 88 × 13mm 115.3 × 80 × 20.9mm
Published weight 98g; Samsung says weight varies by capacity 257g for the 4TB-and-larger body
Interface USB 3.2 Gen 2, 10Gbps USB 3.0
Sequential transfer claim Up to 1,050MB/s read; 1,000MB/s write, under Samsung’s stated conditions No comparable MB/s figure in this sheet
Included cable USB-C–to–C and USB-C–to–A 45.72cm USB 3.0 cable
Limited warranty 3 years 1 year in AMER; 2 in EMEA; 3 in APAC

The 5TB example has 25% more nominal space than the 4TB example. If the retained file set already exceeds 4TB, the 4TB SSD is out before speed enters the decision. A 5TB label still needs headroom: formatted usable capacity is lower than the nominal figure, and retained versions can grow beyond the current file set.

If the required copy fits, the T7 Shield’s smaller body is a concrete reason to consider it for frequent carry. The Seagate’s extra nominal terabyte may matter more for a desk-based retained copy. Neither size nor warranty establishes which drive is more reliable. These published documents also do not establish today’s price or stock; compare the exact capacity and SKU when pricing a purchase.

How long would a 100GB copy take?

Divide the amount to transfer by the sustained rate of the complete copying path. For a decimal 100GB example, use 100,000MB:

Assumed sustained rate Calculation for 100GB Transfer time
100MB/s 100,000 ÷ 100 = 1,000 seconds 16 minutes 40 seconds
500MB/s 100,000 ÷ 500 = 200 seconds 3 minutes 20 seconds

These are hypothetical rates, not benchmarks for the two drives. They show why the copy window matters. If you have ten minutes before leaving, a 100GB transfer needs an average above about 167MB/s even before backup software, scanning or verification adds time. A smaller changed-file backup may be a different job from copying the entire 100GB again.

Samsung’s maximum sequential figures depend on its specified host, cable and system conditions. They are not a promise that a work backup will finish at 1,000MB/s. Many small files, slower source storage, encryption, software and thermal conditions can change the result; Seagate’s USB label supplies no measured backup rate for comparison.

A drive, cable, adapter, dock and computer form one path. Match the required ports, file system, operating system and backup software before buying. Samsung lists both C–C and C–A cables, but a compatible plug does not give every computer 10Gbps. For a docked setup, use the docking-station compatibility guide to locate the relevant host and peripheral ports. Then time one representative, approved test copy through that actual path.

Keep an adequate existing drive if it has the capacity, completes the job in the available window and passes the restore test below. An approved organization-managed or vetted cloud route remains the right choice when policy assigns it, with its own retention, access, network and recovery-owner requirements.

One external drive can hold a copy; it cannot be the entire plan

An external drive beside a laptop can be affected by the same theft, spill, electrical event, mistake, or malware incident. A continuously attached drive can also remain reachable to software acting on the computer. CISA advises storing an external backup safely when it is not in use and avoiding leaving it connected when it is not actively backing up, because ransomware could reach a connected backup.

Add an independent, authorized destination whose failure path is not identical to the portable copy. Depending on policy, that may be an organization-managed backup service, a vetted cloud service with suitable version and recovery behavior, or another controlled storage location. Do not treat a cloud label or synced folder as proof of independence. Read the exact service documentation for retention, version history, deletion behavior, account recovery, export, and administrator responsibilities, then compare those terms with the loss you need to recover from.

Keep the roles visible in the plan:

  • The portable copy solves an approved carry or local recovery need.
  • The independent copy survives a different loss path and has a named owner.
  • The restore procedure explains how either copy becomes usable work again.

If only one of those lines is filled in, the next step is planning or testing—not checkout.

Before you trust the drive, restore the file that matters

Test with approved, non-sensitive data first. Use the intended computer, port or dock, cable, file system, encryption method, backup software, and user account. A useful test ends with an opened and checked file, not a progress bar.

  1. Create or select a representative test set that is permitted on the destination.
  2. Run the intended copy or backup process and record any errors.
  3. Disconnect or otherwise set aside the source so the test does not accidentally open the original.
  4. Restore the test set to the intended recovery location.
  5. Open representative files with the applications that must read them and confirm that required names, folders, permissions, and versions are present.
  6. Record the steps, account or key owner, result, and the condition that should trigger the next test.

Repeat the restore after a meaningful change to the path: a new computer, operating-system upgrade, different dock or cable, changed encryption, replacement drive, new managed service, or revised retention policy. The appropriate schedule depends on how often the files and process change; a universal interval would hide that dependency.

For frequent carry, start with the compact SSD route if the required capacity fits; for a larger retained set, capacity can rule out the smaller example immediately. A short copying window earns a measured speed check, whatever the format. Keep the current or managed route when it already meets the job, and pause a purchase while permission or the restore path is unresolved. Once the device fits those requirements, an independent copy and a successful restore make the plan worth relying on.