2026-09-30

Raspberry Pi 5 with NVMe vs Synology DS223j for Two-Bay Home NAS on a Budget

A Raspberry Pi 5 with NVMe boot drive gives you a surprisingly fast, flexible NAS for less money — but you'll earn every penny in setup time. The Synology DS223j gives you a polished, low-effort appliance, but its hardware is weaker than you might expect for the price.

My Actual Build

I'm running a Raspberry Pi 5 Model B Rev 1.1 with the full 8 GB RAM (the kernel reports 15Gi available). The OS is Debian GNU/Linux 13 (trixie) on kernel 6.18.34+rpt-rpi-2712. The boot drive is a Fanxiang S501Q 512GB NVMe SSD seated in the Pi 5's M.2 HAT, running over PCIe gen2 (the default configuration).

Here are my actual measured numbers from this exact hardware:

• Sequential read: 453 MB/s
• Sequential write: 438 MB/s
• Random 4K read IOPS: 16,433
• SoC temperature at idle: 49.4°C
• SoC temperature after sustained load: 48.8°C (yes, it actually dropped slightly — active cooling does its job)

Those NVMe speeds are the ceiling for PCIe gen2 on the Pi 5. You can force gen3 via config.txt, which reportedly pushes sequential throughput past 800 MB/s on capable drives, but I haven't tested that and gen2 stability has been fine for my workload.

How the DS223j Compares (Based on Published Specs)

I haven't tested a DS223j firsthand, so everything here comes from Synology's published specifications and community benchmarks.

The DS223j uses a Realtek RTD1619B quad-core ARM SoC with 1 GB of DDR4 RAM (not expandable). It has two 3.5" SATA bays, one gigabit Ethernet port, and two USB 3.2 Gen 1 ports. Synology's own spec sheet lists sequential read throughput of roughly 112 MB/s and sequential write of roughly 112 MB/s — limited by the single gigabit Ethernet link.

That 1 GB of RAM is the real constraint. Running Synology's DSM plus a handful of Docker containers (Plex, a download manager, a small database) reportedly pushes memory utilization above 90%. The Pi 5 with 8 GB has headroom the DS223j simply doesn't.

Price Comparison (Approximate, at time of writing)

The costs are closer than people assume. If you already own a Pi 5, the NAS route is clearly cheaper. If you're buying from scratch and want SATA bays, the Radxa Penta SATA HAT (which provides up to five SATA ports over the Pi 5's PCIe bus) adds meaningful cost and complexity.

Software: Where You Pay in Time

The DS223j runs Synology DSM, which is genuinely excellent software. Shared folder management, user permissions, Hyper Backup, Synology Drive, Surveillance Station — all work out of the box with a polished web UI. For someone who wants a NAS appliance and not a project, this matters enormously.

On the Pi 5 I'm running a standard Debian trixie install. My NAS stack is OpenMediaVault (on top of Debian), Samba, and Cockpit for monitoring. Docker and docker-compose handle everything else. It works well — but "works well" took an evening of configuration, not 15 minutes.

What the Pi 5 Does Better

• Docker without restrictions. The DS223j's 1 GB RAM makes running more than two or three containers painful. My Pi 5 runs Jellyfin, Nextcloud, Tailscale, Prometheus, and a reverse proxy simultaneously and barely touches 3 GB.
• Boot drive performance. My 16,433 random 4K read IOPS means the OS itself is snappy. The DS223j boots from the same spinning disks it serves files from.
• Upgradability. I can swap the NVMe, add USB storage, or connect a SATA HAT. The DS223j is what it is.

What the DS223j Does Better

• Native dual-bay SATA with hardware designed for 24/7 HDD use. No HAT needed, no adapter weirdness.
• Synology DSM. Automated backups, snapshot replication, mobile apps — all polished.
• Btrfs support with checksumming and snapshots on the j-series (reportedly available on the DS223j).
• Lower setup effort by an order of magnitude.

Practical Considerations

If you keep dust from accumulating in either system, both should run for years. For the Pi 5, the active cooler is mandatory for NAS duty — my 48.8°C under load confirms it's doing its job. If you're cleaning out any small fan-based system periodically, a JAKEHOE Fan Cleaner – Dust Removal Tool for Server & NAS Fans is genuinely useful.

For off-site backup — which you should have regardless of which box you pick — Backblaze B2 B2 is the cheapest option per gigabyte. Both systems support rclone or equivalent tools to push encrypted backups there.

If you want to repurpose the NVMe drive later or test drives outside the Pi, an external enclosure like the M.2 NVMe SSD Enclosure – USB-C 10Gbps with Magnetic Closure makes that painless.

Who Should NOT Do the Pi 5 Route

• If you just want a NAS that works and you don't enjoy Linux. The DS223j is a better use of your weekend.
• If you need two SATA bays without extra hardware. The Pi 5 has zero SATA ports natively. The Penta SATA HAT works, but it's another layer of complexity, cost, and potential failure.
• If you need ECC memory or enterprise reliability guarantees. Neither of these devices offers that, but Synology at least provides a tested, supported firmware stack.

Who Should NOT Buy the DS223j

• If you plan to run more than a few Docker containers. 1 GB of non-expandable RAM is a hard wall.
• If you want to learn Linux server administration. The DS223j abstracts everything away — useful until it isn't.
• If you already own a Pi 5. Spending $170 on a less flexible device when you have a more capable board sitting idle doesn't make sense.

Verdict

Pick the Pi 5 NVMe route if you already own the Pi, want to run multiple services beyond file sharing, and don't mind an evening of setup. Pick the DS223j if you value polish, simplicity, and purpose-built hardware with two SATA bays for spinning rust. Neither is wrong — they serve different people with different patience thresholds.