Best Budget NAS Build 2026: 4-Bay DIY in the Drive + RAM Crunch

A Synology DS425+ was $599.99 at Newegg on September 23, 2026 with zero storage, and a QNAP TS-464-8G $639.00 empty. Both lock you into proprietary software, both charge extra for features that should be free, and both come with a CPU you'd be embarrassed to put in a laptop. For less, the 5825U box with 16GB of RAM and a boot drive costs $526.78, with eight cores and your choice of operating system.

On the Synology question specifically: the company's 2025 Plus and Value models (DS925+, DS1825+, DS425+) shipped with a drive-compatibility list that threw warnings on third-party Seagate and WD disks and pulled features. Synology reversed course in DSM 7.3 (October 2025) -- third-party drives work again on those 2025 models with full monitoring and alerts, and with every storage feature (mjtsai.com, 2025-10-09). So the drives are not locked today. But Synology framed the reversal as "in the meantime" while it keeps testing additional drives, with no promise that 2026 models stay open. The read: the company walked it back under sales pressure, the lock-in instinct is still there, and building your own box sidesteps the whole question.

The used enterprise hardware crowd will tell you to grab a retired Dell server. Fine, if you want 120W at idle and a machine that sounds like a hair dryer. The smart budget NAS in 2026 is a small 4-bay box with efficient silicon and an OS matched to your actual needs. Here's how to build one.

The Hardware: Two Barebone Boxes That Make Sense

The NAS enclosure market for DIY builders used to be terrible. You either bought a proprietary Synology/QNAP shell or hacked together a desktop case with drive cages. The AOOSTAR WTR Pro changed this. Two models, both with 4 SATA bays, dual 2.5GbE, and compact form factors designed specifically for NAS duty.

Correction, September 24: The watts below are Notebookcheck's idle and load readings for each box. This page had printed them as readings at different drive counts and had called the Intel box an N100; Notebookcheck tested an N150.

AOOSTAR WTR Pro N150 (was N100) — The Efficiency Pick, If You Can Find One

Price: not listed on AOOSTAR's own store on September 23, 2026; $592.99 barebone from a Newegg marketplace seller
CPU: Intel N150 (4C/4T, the N100's Alder Lake-N successor)
RAM: 1× DDR5 SO-DIMM (add your own)
Storage: 4× SATA bays + 1× M.2 NVMe
Network: 2× 2.5GbE

AOOSTAR has superseded the original N100 SKU with an N150 "upgraded N100" variant -- same Alder Lake-N efficiency class, a modest clock bump, the same ~6W-class TDP and Quick Sync iGPU. The Intel N100/N150 is the darling of the low-power homelab world and for good reason. This chip was designed for efficiency-first workloads. Notebookcheck tested an N150 unit (review published May 29, 2025) and measured 9.3W minimum, 14.3W average and 18.7W maximum at idle, and 24.6W average in 3DMark06 with a 27.9W peak in Cinebench R15 Multi. That's the whole system at the wall, CPU and board together.

Four cores, four threads. No hyperthreading. For a NAS serving files over SMB and running a few Docker containers, that's plenty. Where it falls short is heavy transcoding or running a bunch of VMs alongside your storage — the N100 simply doesn't have the threads for it. If your NAS is a NAS and nothing more, the N100 is the right chip.

The M.2 NVMe slot gives you a fast boot drive or ZFS SLOG/L2ARC cache. Dual 2.5GbE means you can bond two links or run one for management and one for data, which matters once your network is upgraded to 2.5GbE.

Availability, September 23, 2026: AOOSTAR's store no longer lists the N150, so a new one comes from marketplace stock: $592.99 barebone from a Newegg marketplace seller. The 5825U at $379 direct is $213.99 cheaper and faster, which is why this guide leads with it.

AOOSTAR WTR Pro 5825U — The Multitasker

Price: $379.00 barebone direct from AOOSTAR on September 23, 2026 (regular $399.95); $512.99 plus $5.99 shipping from a Newegg marketplace seller
CPU: AMD Ryzen 7 5825U (8C/16T)
RAM: 2× DDR4 SO-DIMM, up to 64GB
Storage: 4× SATA bays
Network: 2× 2.5GbE

At $379 direct it is the cheapest new 4-bay AOOSTAR, and the US-warehouse barebone was in stock on AOOSTAR's store on September 23. It comes with eight cores and sixteen threads. The Ryzen 7 5825U is a full mobile processor with real multi-threaded grunt. If you want your NAS to double as a lightweight homelab node (Plex transcoding, a few Docker containers, maybe a small VM), the 5825U gives you the headroom.

The idle power story is more nuanced than the headline numbers suggest. Notebookcheck measured the 5825U WTR Pro at 5.5W minimum, 8.7W average and 13W maximum over a minute at idle, with a Metrahit Energy meter and a monitor attached. Its spec table lists the test unit's storage as one 512GB SSD and the review does not mention hard drives in the power test, so count your drives on top. Those idle numbers are lower than the N150's. minipc-review.com's review (August 22, 2026) prints higher plug readings for the 5825U: 15W to 18W at idle with only NVMe SSDs fitted, and 23W to 24W with four hard drives. It does not say who took them or with what meter.

The catch is load power. Notebookcheck measured the 5825U at 46.2W average in 3DMark06 and a 67.5W peak (the peak came in a Prime95 stress run), against the N150's 24.6W 3DMark06 average and 27.9W Cinebench R15 Multi peak: about 1.9 times the N150's average and 2.4 times its peak. If you're doing heavy transcoding regularly, your electricity bill will notice. If your NAS mostly idles and occasionally serves files, the 5825U's lower idle draw in Notebookcheck's test means it's cheaper to run 24/7 than the N150.

The 64GB DDR4 RAM ceiling is important for TrueNAS builds. ZFS loves RAM, and having two SO-DIMM slots means you can start with 16GB and upgrade to 64GB later by replacing it with two 32GB modules. The N100 model's single DIMM slot is more limiting.

If you need more than four bays or 10GbE, AOOSTAR's newer WTR MAX (Ryzen 7 PRO 8845HS, 6+5 bays, dual 10GbE SFP+, USB4, Oculink) steps up to $659 direct from AOOSTAR (regular $699) on September 23, 2026, and $903.99 from a Newegg marketplace seller. It is past the budget brief here.

Buy the AOOSTAR WTR Pro 5825U barebone: Amazon · Newegg marketplace ($512.99 plus $5.99 shipping) · AOOSTAR direct ($379.00 on September 23, 2026)

Drives: Buy Two Now, Add Two Later

A mirror (RAID 1 / ZFS mirror) gives you redundancy on day one and defers half the drive cost: $659.98 for the IronWolf pair now, and the other two bays stay empty until you need them. Which specific drives to buy (CMR vs SMR, the WD Red Plus vs IronWolf Pro tiers, and the recertified $/TB math) is its own decision, covered in depth in the best NAS hard drives guide.

Seagate IronWolf 8TB (ST8000VN004): Amazon · Newegg, $329.99 at Newegg on September 23, 2026. CMR, 7200 RPM, includes IronWolf Health Management. A mirrored pair is $659.98 for 8TB usable. The faster 7200 RPM spindle runs a little louder.

WD Red Plus 8TB (WD80EFPX): Amazon · Newegg, $345.00 at Newegg on September 23, 2026. Also CMR, 5640 RPM, designed for NAS duty. A mirrored pair is $690.00, $30.02 above the IronWolf pair.

On September 23 the IronWolf was $15.01 a drive cheaper at Newegg, so buy the IronWolf unless the box sits in a room where you will hear a 7200 RPM spindle seek; then the WD is worth the $30.02. For a genuine budget build, recertified enterprise drives go further (see the next section). For drives of 20TB and up, where the rebuild time decides the layout, see the six-bay rebuild math.

The 2026 Drive Question: New, Recertified, or Shuck?

Because drives now dominate the budget, where you buy them is the most important call you'll make. Three routes:

New NAS drives. IronWolf 8TB at $329.99 and WD Red Plus 8TB at $345.00, both at Newegg on September 23, 2026. New retail stock with a manufacturer warranty. Check the exact model and region for coverage; buying new does not establish how loud the array will sound. If your data is irreplaceable and you don't want to babysit drives, pay for new.

Recertified enterprise (Seagate Exos and similar). This is the homelab budget path in 2026, and it's what the r/DataHoarder and r/truenas crowd actually buys during the shortage. Sellers like ServerPartDeals and goHardDrive move recertified enterprise disks at the best dollar-per-TB you'll find. If you're torn between a recertified Exos and a new IronWolf Pro, our NAS hard drive guide prices both in the same table. The caveats: warranties are shorter (often ~1-2 years, seller or limited manufacturer), enterprise 7200 RPM drives idle louder and warmer, and you should run a burn-in test the day they arrive. Redundancy matters more here -- run ZFS or parity and let the array absorb a bad drive. Plan capacity and parity with the NAS & RAID storage calculator, and if you're pairing this with Proxmox, the ZFS on Proxmox guide covers pool layout and scrubs.

Shucking external drives. Pulling the bare drive out of a cheap external enclosure used to be the classic discount move. It still works, but the same shortage that lifted bare-drive prices has compressed the shucking discount, so the savings are thinner than they were in 2024. Worth a look on a deal; don't plan the budget around it.

Picking Your NAS Operating System

The hardware is the easy part. The OS decision is where most people get stuck, and the wrong choice can mean a rebuild six months in. All three are legitimate and built for different users; the four-way comparison with Proxmox goes deeper than this section, and the storage-backend guide covers running one inside the other.

TrueNAS Community Edition — The ZFS Purist

Price: Free (Community Edition)
Minimum RAM: 8GB (for up to 8 drives; more is better)
Filesystem: ZFS (mandatory — it's the entire point)

On the two-drive mirror in this build, an OpenZFS scrub checks stored blocks and can repair a bad block from the good copy. That protects against a different failure than a backup: if you lose the whole box, you need a copy elsewhere.

The RAM requirement is real. ZFS uses ARC (Adaptive Replacement Cache) aggressively, and starving it below 8GB leads to poor performance. The old "1GB of RAM per TB of storage" rule overstates it for a home box: 16GB runs this build's 8TB mirror, and a full 4× 8TB array (32TB raw), with a few apps. The 5825U WTR Pro's 64GB ceiling and dual DIMM slots make it the better TrueNAS chassis.

Community Edition is the Linux line that used to be called SCALE, and its apps run as Docker containers. Version 25.10.7 was the current download on September 23, 2026. The download page also documents the upgrade path from the FreeBSD-based CORE 13.0-U6.8.

Unraid — The Flexibility Play

Price: Starter $49 (6 devices) / Unleashed $109 (unlimited) / Lifetime $249
Minimum RAM: 8GB (16GB+ recommended for VMs)
Filesystem: XFS per drive, parity-based redundancy

Unraid takes a fundamentally different approach to storage. Each drive is an independent XFS filesystem, and parity is calculated across drives. The practical advantage: you can mix drive sizes. A 4TB, an 8TB, and a 12TB can all live in the same array as long as the parity drive is the largest. Try that with ZFS or traditional RAID.

The community app ecosystem is Unraid's real draw. Docker containers and VMs are first-class citizens with a point-and-click interface. Installing Plex, Nextcloud, or Home Assistant is a five-minute affair. For users who want a NAS that does everything and don't want to touch a terminal, Unraid is the most approachable option.

The cost is real but reasonable. The Starter license at $49 covers 6 storage devices: the four bays and a cache SSD, with one to spare. For a 4-bay build, that's all you need. Unleashed at $109 removes the device limit; Lifetime at $249 also includes lifetime updates.

Unraid offers two different layouts here. You can choose a ZFS pool or an individual ZFS disk in the parity array. The individual disk can detect a corrupt block, but it cannot repair that block by itself. For family photos, budget for a separate backup whichever layout you buy.

OpenMediaVault — The Lean Option

Price: Free
Minimum RAM: 1GB (4GB comfortable / 8GB+ recommended)
Filesystem: ext4, XFS, Btrfs, ZFS (via plugin)

OMV is Debian with a web UI for NAS management. That's not a criticism — it's the lightest option by a wide margin. If you want a NAS and nothing else, OMV runs on almost nothing. The 1GB minimum is real: it will function on minimal hardware.

For users who are comfortable in Linux and want a pure NAS without the overhead of TrueNAS or the cost of Unraid, OMV is the right call. It serves SMB and NFS shares, runs rsync jobs and handles basic Docker management. It doesn't try to be a hypervisor or an app platform.

One important note: OMV is not supported in an LXC container. If you're planning to run it inside Proxmox, it needs a full VM. This matters for homelab users who want to consolidate a NAS into an existing Proxmox node.

Sample Builds With Real Costs

Both builds use the prices at the top of this page: the box from AOOSTAR's store and every other part from Newegg, read September 23, 2026. The calculator below adds the same numbers.

Build A: 5825U TrueNAS Mirror — The Reference Build

• AOOSTAR WTR Pro 5825U barebone: $379.00 (AOOSTAR direct)
• Silicon Power 16GB DDR4-3200 SO-DIMM: $93.79 (Newegg)
• Patriot P300 256GB NVMe boot drive: $53.99 (Newegg)
• 2× Seagate IronWolf 8TB, mirrored: $659.98 ($329.99 each, Newegg)

Total: $1,186.76 for an 8TB ZFS mirror: $379.00 plus $93.79 plus $53.99 plus $659.98. The box averaged 8.7W at idle on Notebookcheck's SSD-only test unit, about $14 a year at $0.184/kWh before the drives. minipc-review.com's plug readings (15W to 18W without hard drives, 23W to 24W with four) come to $24 to $39 a year, from 15W with no hard drives to 24W with four.

AOOSTAR specifies DDR4-3200 SO-DIMM memory for the 5825U, so the DDR5 prices elsewhere in this guide do not apply to it; the $93.79 module above is DDR4-3200.

Prefer the N150? Its barebone was $592.99 from a Newegg marketplace seller on September 23, $213.99 above the 5825U, and it takes DDR5 at $229.99 for 16GB. With the same boot drive and drives it comes to $1,536.95.

Build B: 5825U Unraid Multitasker — The Do-Everything Box

• AOOSTAR WTR Pro 5825U barebone: $379.00 (AOOSTAR direct)
• 2× Silicon Power 16GB DDR4-3200 SO-DIMM (32GB): $187.58 ($93.79 each, Newegg)
• Patriot P300 256GB NVMe (cache pool): $53.99 (Newegg)
• 2× Seagate IronWolf 8TB: $659.98 ($329.99 each, Newegg)
• Unraid Starter license: $49 (one-time, six storage devices)

Total: $1,329.55 for 8TB usable with parity protection and a capable app platform ($379.00 plus $187.58 plus $53.99 plus $659.98 plus $49; the calculator below shows the same total for this selection). It is the same box and drives as Build A, so Build A's power figures are the nearest published readings. You get 8 cores of Ryzen grunt for Plex transcoding and Docker workloads (the Plex and Jellyfin NAS guide covers transcoding hardware), plus room to grow to 64GB RAM and four drives. In 2026, "grow to 64GB later" is a real budget line, so size your RAM for what you'll actually run.

Who Should Build What

The 5825U + TrueNAS Build

• You want to use a ZFS mirror and check its integrity with regular scrubs
• You want a compact NAS for files and a few containers, and can check populated noise and power for your room
• You don't need heavy transcoding or VM workloads on the same box
• You're comfortable with TrueNAS's opinionated approach to storage management

The 5825U + Unraid Build

• You want a NAS that also runs Plex, Docker containers, and maybe a Windows VM
• You plan to mix drive sizes as you expand over time
• You prefer a point-and-click interface with a strong community app ecosystem
• The $49 Starter license fits your budget and you want the most approachable setup experience

Either Chassis + OMV

• You want the leanest possible NAS — file sharing and backups, nothing else
• You're a Linux user who's comfortable managing services via a lightweight web UI
• RAM is limited and you don't want ZFS's memory overhead
• Budget is absolutely maximized and even $49 for Unraid matters

The Verdict

On September 23, 2026 the 5825U TrueNAS build costs $1,186.76 with two IronWolf 8TB drives. A Synology DS425+ with the same two drives comes to $1,259.97, and a QNAP TS-464-8G to $1,298.98. The DIY box is $73.21 cheaper than the Synology and brings 16GB of RAM against the DS425+'s 2GB, and eight Ryzen cores against a quad-core Celeron.

The gap is small, so buy the DIY box for its OS flexibility, the RAM and cores, dual 2.5GbE and room to repurpose the hardware. Recertified drives can cut the drive bill further, but the WTR Pro takes SATA drives only: skip SAS listings, and compare warranty as well as price.

Either DIY build lets you change the OS or reuse parts later. For a NAS beside your desk, noise is a separate decision. Synology lists 21.6 dB(A) for the DS425+, measured at idle with SSDs and microphones one metre away. That does not rank it against a WTR Pro seeking across two hard drives. Before paying extra for a quieter machine, look for both units measured at the same distance with the same drives running the same workload.