HDD|Hunt

HDD vs SSD for NAS

HDDs have dominated NAS storage for decades thanks to their unbeatable cost per terabyte. But SSD prices are dropping and all-flash NAS builds are becoming viable for some use cases. This page compares both technologies side by side, sorted by price per TB, so you can make the right choice for your specific NAS workload.

The NAS storage trade-off

A 4-bay NAS with 16 TB HDDs gives you 64 TB raw, or 48 TB usable with single parity. The same 4 bays with 4 TB SSDs gives you 16 TB raw. HDDs deliver several times more storage per dollar spent. SSDs deliver silent operation, lower power draw, faster random I/O, and no vibration concerns. Most NAS builders choose HDDs for the data pool and add one or two SSDs as cache. The comparison below prices both against today's listings.

Quick Verdict

Who this is for
NAS builders deciding between HDD-based, SSD-based, or hybrid storage configurations for Synology, QNAP, TrueNAS, or Unraid.
What usually wins
HDDs for bulk storage (media, backups, file shares). SSDs for cache, metadata, or all-flash pools where IOPS matter (VMs, databases, Docker volumes). A hybrid approach (HDD data pool with SSD cache) is the most cost-effective for most home and small-office NAS setups.
Prioritise
Cost per usable TB for your data pool. Random I/O performance for your application tier. Most NAS workloads are sequential and throughput-limited by the network, not the drives.

Prices updated daily from Amazon.com. All links go directly to the retailer. Details.

Bottom line: the lowest price-per-TB pick on this page right now is the Avolusion HDDGEAR PRO 14TB 7200RPM USB 3.0 External Hard Drive (for Windows or MacOS, Desktop & Laptop), 14 TB new, at $299.99 ($21.43/TB) on Amazon.com. Check the current price.

Cheapest NAS HDDs per TB

NAS-rated hard drives offering the most storage per dollar, the default choice for bulk NAS capacity.

$20.00/TB New

HUS726040ALS210 HGST 4TB 7.2K 12G LFF SAS Hard Drive

4 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$79.99 Amazon US· 1h 57m
$20.00/TB New

HP 857966-001 HPE 10TB SAS 12G MIDLINE 7.2K LFF

10 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$200.00 Amazon US· 51m
$21.43/TB New

Avolusion HDDGEAR PRO 14TB 7200RPM USB 3.0 External Hard Drive (for Windows or MacOS, Desktop & Laptop)

14 TB External 3.5" USB
$299.99 Amazon US· 1h 20m
$21.67/TB New

MDD MAXDIGITALDATA MDD 18TB 7200RPM 256MB Cache SAS 12.0Gb/s 3.5inch Internal Enterprise Hard Drive (MDD18TSAS25672E) - [Not a SATA HDD]

18 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$389.99 Amazon US· 3h 13m
$23.00/TB New

MDD 10TB 7200RPM 256MB Cache SAS 12.0Gb/s 3.5inch Internal Enterprise Hard Drive (MDD10TSAS25672E) - [NOT A SATA HDD]

10 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$229.99 Amazon US· 3h 43m
$23.06/TB New

1PCS for 10T SAS 7.2K 3.5" Server Hard Disk ST10000NM0096

10 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$230.63 Amazon US· 42m
$23.57/TB New

Avolusion PRO-H1 Series 14TB 7200RPM USB 3.2 Gen2 (10Gbps) External Hard Drive (for Windows or MacOS Desktop PC/Laptop)

14 TB External 3.5" USB
$329.99 Amazon US· 1h 9m
$23.80/TB New

HP 3.5-Inch 4000 GB Hot-Swap 2 MB Cache Internal Hard Drive 693687-B21

4 TB Internal 3.5" SATA
$95.18 Amazon US· 2h 45m

Cheapest SSDs for NAS Use per TB

SATA and NVMe SSDs for all-flash NAS builds, SSD cache, or metadata tiers.

$45.99/TB New

VIREXEL External Solid State Drives, 1TB Portable SSD USB 3.0 (1, Silver)

1 TB External SSD USB
$45.99 Amazon US· 2h 23m
$64.95/TB New

XISHUO NVMe SSD Internal Solid State Drive

2 TB M.2 2280 PCIe
$129.90 Amazon US· 3h 28m
$65.00/TB New

X5 Data Pro 2TB 2.5" SATA III SSD (NOT NVMe/M.2) – Budget Internal Solid State Drive for Laptop & Desktop – Basic Performance Storage

2 TB Internal 2.5" SATA
$129.99 Amazon US· 48m
$74.00/TB New

SAN ZANG MASTER Magnetic Portable Solid State Drives: Ultra-Thin, Portable Design for Secure Grip, Easy Connectivity, and Reliable Performance (2, TB)

2 TB External SSD USB
$147.99 Amazon US· 2h 3m
$83.33/TB New

BUSlink DL-3T8SDU3XP 3.8TB XP Compatible Disk-On-The-Go Slim Portable External SSD – USB 3.0 Bus-Powered 2.5" Compact Travel-Friendly Backup Storage, for Windows XP to Windows 11, Mac & Linux

3.8 TB External 2.5" USB
$319.99 Amazon US· 1h 23m
$84.00/TB New

Lufasnd Internal 4TB SATA SSD, 2.5 Inch SSD SATA III 6Gb/s, Solid State Drive, Up to 520MB/s Read Speed, 3D NAND Flash, Compatible with Laptop & Desktop PC

4 TB Internal 2.5" SATA
$335.99 Amazon US· 3h 12m
$84.74/TB New

KingSpec 4TB 2.5 SSD SATA III Internal - 550MB/s Read, 520MB/s Write with 3D NAND Flash, for Laptop & Desktop PC Upgrade

4 TB Internal 2.5" SATA
$338.97 Amazon US· 4h 4m
$85.00/TB New

GiGimundo 2TB Magnetic Portable SSD, External SSD Up to 2000MB/s with USB-C 3.2 Gen 2x2, 4K ProRes HDR Record and Store, External Solid State Drives Compatible with iPhone 17/16/15 Pro Max, Tablet

2 TB External SSD USB
$169.99 Amazon US· 2h 3m

High-Capacity NAS HDDs (12 TB+)

Large NAS drives for maximum density per bay, fewer drives, less power, simpler management.

$21.43/TB New

Avolusion HDDGEAR PRO 14TB 7200RPM USB 3.0 External Hard Drive (for Windows or MacOS, Desktop & Laptop)

14 TB External 3.5" USB
$299.99 Amazon US· 1h 20m
$21.67/TB New

MDD MAXDIGITALDATA MDD 18TB 7200RPM 256MB Cache SAS 12.0Gb/s 3.5inch Internal Enterprise Hard Drive (MDD18TSAS25672E) - [Not a SATA HDD]

18 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$389.99 Amazon US· 3h 13m
$23.57/TB New

Avolusion PRO-H1 Series 14TB 7200RPM USB 3.2 Gen2 (10Gbps) External Hard Drive (for Windows or MacOS Desktop PC/Laptop)

14 TB External 3.5" USB
$329.99 Amazon US· 1h 9m
$24.29/TB New

Avolusion PRO-T8 Series 14TB USB 3.0 External Hard Drive for WindowsOS Desktop PC/Laptop (Black) - 2 Year Warranty

14 TB External 3.5" USB
$339.99 Amazon US· 1h 10m
$24.90/TB New

BUSlink U3-20TS 20TB HDD USB 3.2 Gen 1 5Gbps/eSATA External Desktop Drive

20 TB External 3.5" USB
$498.00 Amazon US· 49m
$24.94/TB New

Water Panther 16TB 7.2K RPM SAS 12Gb/s 3.5" HDD for Dell PowerEdge Servers | Enterprise Hard Drive in 14G Tray

16 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$399.00 Amazon US· 1h 50m
$24.94/TB New

Water Panther 16TB 7200 RPM SAS 12Gb/s 3.5-Inch Enterprise Hard Disk Drive in 12G 13G Tray Compatible with Dell PowerEdge Servers R730XD R730 T340 T330 T640 T630 T440

16 TB Internal 3.5"

SAS interface. Needs a host bus adapter, it will not plug into a normal motherboard.

$399.00 Amazon US· 2h 37m
$25.00/TB New

MDD MAXDIGITALDATA 20TB 7200 RPM 256MB Cache SATA 6.0Gb/s 3.5'' Internal Hard Drive (for NAS, Network Storage) - 5 Years Warranty

20 TB Internal 3.5" SATA
$499.99 Amazon US· 21m

How to Choose

Choosing between HDD and SSD for NAS depends on your workload, budget, and noise tolerance.

Cost per TB

At high capacities an HDD costs several times less per terabyte than a NAS-grade SSD. For bulk storage (media servers, backups, file shares), that cost advantage is decisive. SSDs only make financial sense for high-IOPS workloads where you need the performance.

Noise and vibration

Spinning HDDs generate audible noise (25–35 dBA) and vibration, especially in multi-bay enclosures. SSDs are completely silent with zero vibration. If your NAS sits in your living space, this is a meaningful quality-of-life factor.

Power consumption

A typical NAS HDD draws 5–8W under load. A SATA SSD draws 2–3W. Over 4–8 drives running 24/7, the power difference adds up to $20–60/year in electricity. Not transformative, but worth noting for always-on setups.

Network bottleneck

A 1 GbE NAS maxes out at ~110 MB/s. Even a single HDD can saturate this. 2.5 GbE (280 MB/s) is within HDD RAID capability. You need 10 GbE to benefit from SSD speeds in a NAS context. If your network is 1 GbE, SSDs offer no throughput advantage for file serving.

Frequently Asked Questions

Should I use HDDs or SSDs in my NAS?

For most builds, HDDs for the data pool and one or two SSDs as cache. HDDs deliver several times more storage per dollar, which is decisive for bulk media, backups, and file shares; SSDs earn their place for high-IOPS tiers (VMs, databases, Docker) or all-flash pools. A hybrid HDD-pool-plus-SSD-cache setup is the most cost-effective for typical home and small-office NAS. The table on this page prices both against today’s listings.

Are SSDs worth it in a NAS?

Only where IOPS matter. A 4-bay NAS with 16 TB HDDs gives 64 TB raw; the same bays with 4 TB SSDs give just 16 TB, at far higher cost. Most NAS workloads are sequential and limited by the network, not the drives, so all-flash pays off mainly for VM storage, databases, or metadata-heavy workloads — not for a media server.

Will SSDs make my NAS faster?

Usually not for file serving, because the network is the bottleneck. A 1 GbE NAS maxes out around 110 MB/s — a single HDD can already saturate that. Even 2.5 GbE (280 MB/s) is within reach of an HDD array. You need 10 GbE before SSD speeds actually show up in NAS file transfers; below that, SSDs add cost without throughput.

Do HDDs use more power than SSDs in a NAS?

Yes, modestly. A NAS HDD draws about 5–8W under load versus 2–3W for a SATA SSD. Across 4–8 drives running 24/7 that is roughly $20–60/year more in electricity — worth noting for an always-on build, but small next to the several-fold capacity cost advantage HDDs hold.

What about noise and vibration?

HDDs spin, so they generate audible noise (about 25–35 dBA) and vibration, which is more noticeable in multi-bay enclosures. SSDs are silent with zero vibration. If your NAS lives in a bedroom or living room, that is a real quality-of-life factor — one reason some people accept the cost of a hybrid or all-flash build.