Comparison · Home-office document scanning

NAS or External Drive? Buy for Sharing and Backup

Research reviewed.How I test

AI illustration of generic network storage and a separate USB drive on a desk; not the named products. — AI illustration

The short answer

Choose a NAS when several devices need shared files or centrally managed backups. Choose an external drive for a simpler direct connection to one computer. A NAS still needs its own backup, and a diskless enclosure needs storage drives before it can hold your files.

Compare specifications

Compare the details

Shared storage or a direct backup drive?

Evidence notes · 2026-09-09

Published manufacturer details, with practical findings from our research. Source dates and any unresolved details are shown below. Digital Derek has not hands-on tested these products.

A NAS earns its place through sharing
Buy for several devices and a routine you will manage. One computer may be well served by a direct USB drive. [1] [2]
Diskless means budget for drives
The enclosure price does not include its storage drives. Usable capacity depends on the drive and RAID choices. [1]
Keep another independent copy
Files stored only on the NAS still need a backup elsewhere. RAID and a second independent copy serve different purposes. [1] [3]

Shared storage or a direct backup drive?. Published specifications are not Digital Derek test results.
Feature	Synology DiskStation DS225+ · DisklessDetails ↓Shared storage for several devices	Samsung T7 Shield 2TB (Black)Details ↓Portable SSD for regular transfers
Main connection Why it matters Shared access and a direct connection solve different jobs.	Network: 2.5GbE + 1GbE portsPort ratings are not file-transfer results. Source notes manufacturer specification [1]Checked 2026-09-09	USB 3.2 Gen 2Actual transfers depend on computer, cable and workload. Source notes manufacturer specification [2]Checked 2026-09-09
What the box provides Why it matters Budget for usable storage, not empty bays.	Two bays; storage drives separate Source notes manufacturer specification [1]Checked 2026-09-09	2TB installed storage Source notes manufacturer specification [2]Checked 2026-09-09
Managing files Why it matters Choose how much administration you want.	DSM file-sharing and backup packages Source notes manufacturer specification [1]Checked 2026-09-09	Direct-attached drive Source notes manufacturer specification [2]Checked 2026-09-09
Power source Why it matters Decide where the drive will live.	External AC power supply Source notes manufacturer specification [1]Checked 2026-09-09	USB bus power Source notes manufacturer specification [2]Checked 2026-09-09
Device dimensions Why it matters Allow room for cables and ventilation.	165 × 108 × 232.2 mmEnclosure dimensions; installed drives add weight. Source notes manufacturer specification [1]Checked 2026-09-09	88 × 59 × 13 mmDrive dimensions without cable. Source notes manufacturer specification [2]Checked 2026-09-09
Changing storage Why it matters Think about growth without treating raw bays as usable capacity.	Two SATA drive bays Source notes manufacturer specification [1]Checked 2026-09-09	Fixed 2TB capacity for this version Source notes manufacturer specification [2]Checked 2026-09-09

Select a model name for its fit, main tradeoff and retailer link.

All 6 specifications shown.

Sources for this comparison

The findings above interpret published specifications for different uses. They are not hands-on results.

Synology DS225+ hardware and software specifications · manufacturer specification · evidence reviewed 2026-09-09
Samsung T7 Shield Rev. 2.0 data sheet · manufacturer specification · evidence reviewed 2026-09-09
Seagate: what counts as a backup · manufacturer support · evidence reviewed 2026-09-09

At a glance

Your options at a glance

Choose the fit that matches your routine, then check the exact product.

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Shared storage for several devices

Synology DiskStation DS225+ · Diskless

Best for: Households that want shared files and centrally managed backups.
Why it made the shortlist: Two drive bays and Synology software provide a shared destination across the home network.
The catch: Drives are sold separately; choose compatible drives and keep an independent backup.

Portable SSD for regular transfers

Samsung T7 Shield 2TB (Black)

Best for: Frequent large-file work and a drive that travels with a compatible computer.
Why it made the shortlist: USB 3.2 Gen 2 and a solid-state design suit repeated transfers without a spinning mechanism.
The catch: Maximum speed depends on the host, cable and workload. Keep another independent copy of important files.

If one laptop needs a scheduled backup, an external drive can be a straightforward fit. If several computers and phones need a shared home for files, moving a USB drive between them soon becomes a different kind of work.

A NAS connects storage to the network and adds management software. That can support shared folders and device backups, but it also introduces accounts, updates, drive choices and a recovery plan. Buy for a routine you want to maintain, not because a network box looks more professional.

For shared storage: Synology DiskStation DS225+

The Synology DS225+ diskless enclosure has two SATA drive bays and separate 2.5GbE and Gigabit network ports. Synology's specifications describe file-sharing and backup packages within DSM. Those capabilities make it a useful candidate when several devices need a common destination.

The catch: diskless means the storage drives are separate purchases. Choose the exact drives against Synology's current compatibility list, then calculate usable capacity for the configuration. Two drives set up as a mirror do not provide the sum of both drives as usable file space.

Avoid relying on older blanket advice that every 2025 Plus model requires only Synology-branded hard drives. The manufacturer's DSM 7.3 announcement expanded installation and storage-pool support for third-party drives. Support and validation still depend on the current policy and exact drive; the change is not a promise that every drive is suitable.

For a direct connection: Samsung T7 Shield 2TB

The Samsung T7 Shield 2TB is an external SSD example for one computer's file transfers and backups. Its data sheet specifies USB 3.2 Gen 2 and a compact, bus-powered design. Connect it directly or through a suitable port; a NAS enclosure is not required.

The catch: the drive is a destination, not a backup schedule. Choose software and a routine that keep another copy of the files you need. If lower purchase cost per capacity matters more than frequent transfers, compare current HDD offers using the SSD versus external HDD guide. An external drive can be either type.

Give the NAS its own backup

A drive mirror can help the NAS keep working after certain disk failures. It does not create an independent copy safe from everything that affects the box. If the only copy of a photo has moved onto the NAS, it needs a second destination.

Seagate explains the distinction between storage and another copy. Synology also documents backup destinations including external drives and cloud storage. Choose what you can restore after accidental deletion or loss of the main device, and test a few restored files before trusting the routine.

Compare the complete setup

For the NAS route, count the enclosure, suitable drives, an independent backup destination and any required network equipment. For the external route, count the drive, a compatible connection and the backup software you will use. Port speed labels are not a promise of real file-transfer speed.

A UPS can address power interruptions; it does not replace another copy of your files. Buy shared storage when sharing saves repeated work. Keep the simpler direct-drive route when it comfortably meets the job.

Page details

Research sources

Published: Sep 9, 2026
Sources checked: Sep 9, 2026
Written by: Derek Solas

Keep solving the same problem

NAS or External Drive? Buy for Sharing and Backup

Shared storage or a direct backup drive?

A NAS earns its place through sharing

Diskless means budget for drives

Keep another independent copy

Sources for this comparison

Your options at a glance

Synology DiskStation DS225+ · Diskless

Samsung T7 Shield 2TB (Black)

For shared storage: Synology DiskStation DS225+

For a direct connection: Samsung T7 Shield 2TB

Give the NAS its own backup

Compare the complete setup

More on home-office document scanning

Make the next buying decision easier.

The short answer

Shared storage or a direct backup drive?

A NAS earns its place through sharing

Diskless means budget for drives

Keep another independent copy

Sources for this comparison

Your options at a glance

Synology DiskStation DS225+ · Diskless

Samsung T7 Shield 2TB (Black)

Sharing is the reason to consider a NAS

For shared storage: Synology DiskStation DS225+

For a direct connection: Samsung T7 Shield 2TB

Give the NAS its own backup

Compare the complete setup

More on home-office document scanning

Make the next buying decision easier.