Raspberry Pi NAS: Is It Actually Worth It?

You've got a spare Pi 4 in a drawer, or you're eyeing a Pi 5 and wondering if it can replace a "real" NAS. Every tutorial online will show you how to build one. Almost none will show you the numbers that decide whether you should.

The honest answer depends entirely on your bottleneck, and that bottleneck is different on a Pi 4 than a Pi 5. So before any setup instructions, here's the data.

TL;DR

Pi 4 tops out around 105-113 MB/s over USB 3.0/Samba — fine for backups, tight for anything else.
Pi 5 with native PCIe (NVMe or SATA HAT) pushes 450-900 MB/s locally, but a plain gigabit port still caps network transfers near 118 MB/s.
A Pi NAS idles at under 3 watts — a fraction of a mini PC or a purpose-built 2-bay NAS, saving real money over a year.
It genuinely falls short for multi-user households, parity RAID, and Plex transcoding.

The numbers first

Here's what independent testing actually measured, not marketing throughput.

Path	Real-world throughput	Source
Pi 4 USB 3.0, local SSD read/write	113.1 MB/s / 68.6 MB/s	unixetc.co.uk
Pi 4 Samba over gigabit, read/write	105.0 MB/s / 64.7 MB/s	unixetc.co.uk
Gigabit Ethernet ceiling (protocol overhead)	~118 MB/s theoretical, ~111-116 MB/s practical	rickardnobel.se
Pi 5 NVMe, PCIe Gen 2 (default)	~450 MB/s	jeffgeerling.com
Pi 5 NVMe, PCIe Gen 3 (forced/overclocked)	~900 MB/s	jeffgeerling.com
Pi 5 + Radxa Penta SATA HAT, 4-drive RAID 0	800-850 MB/s	pipci.jeffgeerling.com

KEY-STAT: 118 MB/s — the gigabit Ethernet ceiling every Pi NAS eventually hits, regardless of drive speed

Notice the pattern: raw drive throughput on a Pi 5 can hit 900 MB/s locally, but the moment that data has to leave over a single gigabit port, it's throttled to roughly an eighth of that. Local speed and network speed are two different ceilings.

Why the Pi 4 hits a wall

USB 3.0's spec ceiling is 5 Gbit/s, or about 500 MB/s after encoding overhead, according to the USB 3.0 spec summary. Nobody gets close to that on a Pi 4 NAS.

Real Samba transfers land at 105.0 MB/s read and 64.7 MB/s write, per independent testing on unixetc.co.uk. Reads nearly saturate gigabit Ethernet. Writes lag well behind — the write path has to cross USB 3.0's shared controller, hit the SD card or attached drive, and confirm the write before acknowledging, and that round trip is where the asymmetry comes from.

The Pi 4 did fix one real bottleneck from the Pi 3 era: the Raspberry Pi USB bus documentation confirms the Pi 3 shared a single combined USB+Ethernet controller capped near 300 Mbps total. The Pi 4 split Ethernet onto its own transceiver and gave USB 3.0 a dedicated VL805 controller — which is exactly why it can reach 100+ MB/s at all.

Note

For a single-user backup target or a slow-and-steady media library, 65-105 MB/s is genuinely fine. It's roughly 4-8x faster than most home internet upload speeds, so remote access was never the limit anyway.

The Pi 5 changes the math

The Pi 5's headline upgrade for storage is a native PCIe interface, not a faster USB port. An NVMe HAT or a SATA HAT like the Radxa Penta bypasses USB entirely.

At the default PCIe Gen 2 negotiation, Jeff Geerling measured roughly 450 MB/s from a single NVMe SSD. Forcing the (unsupported) Gen 3 speed nearly doubled that to about 900 MB/s. With four drives in RAID 0 on the Radxa Penta SATA HAT, independent testing on pipci.jeffgeerling.com recorded 800-850 MB/s sequential reads.

None of that reaches the network at full speed. A plain gigabit port still caps outbound transfers near 118 MB/s (Wikipedia, Gigabit Ethernet), so unless you add a 2.5GbE USB adapter or a Pi 5 HAT with a faster NIC, the local PCIe speed only matters for on-device tasks — parity checks, local transcoding scratch space, or serving multiple simultaneous local clients that each get a share of that gigabit pipe.

In my homelab I run the bulk of my storage on a Proxmox box with proper SATA and 10GbE, precisely because I hit this ceiling with SBC-based storage years ago — the drive was never the bottleneck once more than one client was pulling from it at once.

Real running cost: idle power at €0.35/kWh

This is where a Pi NAS actually wins, and it's rarely quantified. Here's the idle draw for each option, run 24/7 for a year at a typical German household rate of €0.35/kWh.

Device	Idle power	Annual cost (24/7 @ €0.35/kWh)
Raspberry Pi 4	~2.9 W	€8.89
Raspberry Pi 5 (headless)	~2.7 W	€8.28
Intel N100 mini PC	~6-8 W	~€21.46
2-bay purpose-built NAS, 2 HDDs	~20-30 W (idle-to-active)	€61.32-€91.98

Power figures for the Pi 4 and Pi 5 come from raspberry.tips' 2026 power consumption testing; the N100 range from selfhosting.sh's mini PC measurements; the 2-bay figure is built from Synology's own per-drive access wattage (~20 W base plus ~5 W per spinning HDD).

The math for the Pi 5 line, shown in full:

2.7 W × 8,760 hours/year ÷ 1,000 = 23.65 kWh/year
23.65 kWh × €0.35/kWh = €8.28/year

A Pi 5 NAS costs under €9 a year to keep running, idle, 24/7. That's roughly a tenth of what a spinning-disk NAS costs just to sit there waiting for a file request — before you factor in the Pi's much lower purchase price.

Tip

Under real load the gap narrows — the Pi 5 can hit ~8.8 W on CPU load and up to ~16 W under a heavy combined workload (raspberry.tips) — but a home NAS spends the overwhelming majority of its life idle, so the idle figure is what actually shows up on your bill.

Setting one up: OpenMediaVault in about 15 minutes

OpenMediaVault (OMV) is the default NAS OS for this setup — free, web-managed, and built on Debian. Flash Raspberry Pi OS Lite (no desktop) with Raspberry Pi Imager, enable SSH, then install with the official one-liner documented by Pi My Life Up:

wget -O - https://github.com/OpenMediaVault-Plugin-Developers/installScript/raw/master/install | sudo bash

The script runs for roughly 30 minutes and reboots automatically. After that, the web UI handles shares, users, and (via the OMV-Extras plugin) Docker and Portainer for anything beyond plain file serving.

Once it's running, a quick sanity check on real throughput beats trusting any spec sheet — an fio or dd pass from a client machine tells you what you'll actually get:

dd if=/dev/zero of=/mnt/nas-share/testfile bs=1M count=2048 oflag=direct status=progress

Warning

A Pi NAS is not a backup. Whatever redundancy scheme you run — mirrored drives, snapshots, whatever — a single Pi with one power supply and one SD card is still one device. If it's your only copy of anything irreplaceable, you don't have a backup, you have a single point of failure with extra steps.

Where a Pi NAS genuinely falls short

Multi-user access. Gigabit bandwidth is shared. Two people pulling large files simultaneously each get roughly half the ~118 MB/s ceiling — noticeable the moment more than one household member is active.

Parity RAID. Software RAID (mdadm) on an SBC works, but rebuilds are slow and CPU-bound. Running several drives off one USB or HAT power rail also raises the odds of an undervoltage event mid-rebuild — a risk purpose-built NAS enclosures design around with dedicated per-drive power.

Plex transcoding. The Pi 5's GPU can hardware-decode HEVC, but there's no hardware encoder, so transcoding falls back to software — the CPU throttles fast, and 4K playback for an incompatible device often just fails outright.

Beyond gigabit. Without an add-on 2.5GbE adapter, every Pi NAS — Pi 4 or Pi 5 — shares the same ~118 MB/s network ceiling no matter how fast the internal storage is.

For any of these, a small mini PC built as a home server or a dedicated storage OS covered in our TrueNAS vs Unraid comparison is the better foundation — more CPU headroom for transcoding, real SATA lanes, and mature RAID tooling.

The honest verdict

A Raspberry Pi NAS is worth building if you want a single-user backup target, a lightweight file share, or a first step into self-hosting — the running cost is close to nothing and the setup is genuinely quick.

It falls short the moment you add a second regular user, want parity RAID you can trust, or plan to transcode video for devices that don't support your library's codecs directly.

If you're weighing this as your very first self-hosted box, our beginner's guide to building a homelab walks through where storage fits into the bigger picture — and whether to start with a Pi at all or jump straight to a small dedicated machine.

FAQ

Is a Raspberry Pi fast enough to be a NAS?

For single-user backups and light file sharing, yes — a Pi 4 sustains 65-105 MB/s over Samba, and a Pi 5 with PCIe storage goes considerably higher locally. For multiple concurrent users or heavy workloads, it becomes the bottleneck.

How much power does a Raspberry Pi NAS use per year?

A Pi 5 idling at roughly 2.7 W costs about €8.28 a year running 24/7 at €0.35/kWh; a Pi 4 at roughly 2.9 W costs about €8.89 a year. Both are far cheaper to run than a spinning-disk NAS or a mini PC.

Can a Raspberry Pi 5 NAS run Plex?

It can serve files fine, but it lacks a hardware video encoder, so transcoding for incompatible devices runs in slow software and 4K often fails. Direct-play-only libraries work much better than transcode-heavy ones.

Is a Raspberry Pi NAS reliable for backups?

It can hold a backup copy, but a single Pi with one power supply and storage device is not redundancy by itself. Treat it as one copy in a proper 3-2-1 backup scheme, not your only copy.

Raspberry Pi 4 or Pi 5 for a NAS build?

The Pi 5 is the better choice if you want PCIe-attached NVMe or SATA storage and higher local throughput. The Pi 4 is still viable and cheaper for a simple USB 3.0 single-drive setup within its ~65-113 MB/s range.