Businesses that want a NAS appliance that delivers capacity, performance and features will find a huge range of multi-bay systems to choose from and both Qnap and Synology offer impressive portfolios of high-end appliances. In this review we pitch two of their latest desktop leviathans against each other, reveal their positives and negatives and put them through their paces in the lab to help you choose the right one for your network storage needs.

Appliance specifications

It pays to buy the best hardware specification you can afford as this will future-proof your investment when you ask your NAS appliance to do more. CPU power and memory are important as both these appliances are capable of running a wide variety of apps and the more you load on them, the higher the hardware demands become.

 

Synology’s DS1621xs+ is powered by a 2.2GHz Intel Xeon D-1527 CPU and the price includes 8GB of DDR4 ECC server-grade memory which can be upgraded to 32GB. When it comes to memory upgrades, Synology is particularly picky as you must use its own 8GB and 16GB modules otherwise you risk invalidating the product warranty.

 

Don’t be put off by its elderly Xeon D-1527 CPU as it may be over five years old but still offers plenty of horsepower. In fact, our lab tests show the DS1621xs+ is capable of delivering a superb performance.

 

The TS-h973AX is one of Qnap’s first desktop appliances to use an AMD Ryzen V1500B CPU which also has a base clock speed of 2.2GHz. There aren’t any significant differences between this and the Xeon D-1527 as they are both quad-core, multi-threaded CPUs although the Ryzen has a smaller TDP of 16W so will consume less power.

 

The base 8GB of DDR4 ECC memory in the TS-h973AX can be expanded up to 64GB and Qnap appears to be easy-going about what memory you can use as its compatibility list doesn’t even mention certified modules. Qnap also offers a 32GB version of this appliance and we’ll explain further on why you may need to consider this one.

Compare Specs

Priced from $1,089

TS-h973AX vs DS1621xs+Head to Head Comparison
VS
CPU Model
AMD Ryzen V1500B
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Intel Xeon D-1527
CPU Architecture
64-bit x86
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64-bit x86
CPU Frequency
2.2GHz
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2.2GHz
CPU Cores
4
VS
4
Base System MemoryDDR4 ECC UDIMM
8 GB
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8 GB
MemoryExpandable up to
64GB
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32GB
Drive BaysTotal
5 x LFF/SFF, 4 x SFF
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6 x LFF/SFF
2.5GbE Ports(2.5G/1G/100M)
2
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10Gbe Ports10GBase-T
1
VS
1
Expansion slotStandard
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1 x PCIe Gen3 x8
NVMe SSD support
2 x U.2
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2 x M.2
Operating System
Qnap QuTS hero
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Synology DSM
WarrantyManufacturer warranty
3 year
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5 year

Priced from $1,645

Compare QNAP TS-h973AX with Synology DS1621xs+

Specification Comparison and Reviews

Storage features

As NAS appliances become more versatile, the amount of network traffic they are generating and handling can easily swamp a Gigabit connection. Multi-Gigabit ports provide an easy upgrade as you can more than double network speeds over your existing Cat5e/Cat6 wiring infrastructure.

 

TS-973AX rear view

TS-h973AX – click to enlarge

 

QNAP is the multi-Gigabit champion as most of its latest NAS appliances sport 2.5GbE ports and the TS-h973AX offers a pair of them. There’s more as it provides an embedded 10GBase-T copper port which is also multi-Gig capable.

DS1621xs+ Rear view

DS1621xs+ – click to enlarge

Synology has traditionally eschewed multi-Gigabit and favors a mix of Gigabit and 10GbE. The DS1621xs+ is Synology’s first Intel-powered model to sport an embedded 10GBase-T port and it partners this with a pair of Gigabit ports.

 

The DS1621xs+ has a superior expansion potential. Unlike the TS-h973AX, it offers a PCI-E slot and Synology’s compatibility list includes plenty of industry standard single and dual-port copper and fiber 10GbE adapters.

 

You can expand storage outside the box as both appliances support external disk enclosures with the TS-h973AX handling two USB-attached four-bay TR-004U units. The DS1621xs+ supports up to two 5-bay DX517 expansion units and a small advantage is they connect to the main unit via its pair of eSATA ports so you don’t lose any USB ports.

Networking and expansion potential

As NAS appliances become more versatile, the amount of network traffic they are generating and handling can easily swamp a Gigabit connection. Multi-Gigabit ports provide an easy upgrade as you can more than double network speeds over your existing Cat5e/Cat6 wiring infrastructure.

 

Qnap is the multi-Gigabit champion as most of its latest NAS appliances sport 2.5GbE ports and the TS-h973AX offers a pair of them. There’s more as it provides an embedded 10GBase-T copper port which is also multi-Gig capable.

 

Synology has traditionally eschewed multi-Gigabit and favors a mix of Gigabit and 10GbE. The DS1621xs+ is Synology’s first Intel-powered model to sport an embedded 10GBase-T port and it partners this with a pair of Gigabit ports.

 

The DS1621xs+ delivers amazing 10GbE performance

The DS1621xs+ delivers amazing 10GbE sequential and random read performance for IP SANs

 

The DS1621xs+ has a superior expansion potential. Unlike the TS-h973AX, it offers a PCI-E slot and Synology’s compatibility list includes plenty of industry standard single and dual-port copper and fiber 10GbE adapters.

 

You can expand storage outside the box as both appliances support external disk enclosures with the TS-h973AX handling two USB-attached four-bay TR-004U units. The DS1621xs+ supports up to two 5-bay DX517 expansion units and a small advantage is they connect to the main unit via its pair of eSATA ports so you don’t lose any USB ports.

NAS and IP SAN 10GbE performance

For performance testing, we loaded each appliance with Seagate IronWolf NAS hard disks and created RAID5 storage pools. Our test host was a Dell PowerEdge T640 Xeon Scalable tower server equipped with 10GbE ports and running Windows Server 2019.

 

 

DS1621xs+ delivered superior NAS performance over the TS-h973AX

 

The DS1621xs+ delivered superior NAS performance as although both appliances returned nearly identical sequential read rates for a mapped share, Synology was noticeably faster for write operations. There was nothing between them for IP SAN performance with both appliances returning high throughputs for a single 10GbE connection to a 500GB iSCSI target.

 

DS1621xs+ triple 10GbE MPIO link to the iSCSI target

 

As the DS1621xs+ has a PCIe expansion slot, we took the opportunity to push it to the limit by installing a Broadcom dual-port 10GbE card. With a triple 10GbE MPIO link to the iSCSI target, Synology delivered stunning results with Iometer reporting huge sequential read and write speeds both of 26.7Gbits/sec, clearly showing that the Xeon D-1527 CPU was up to the challenge.

 

 

Real world 10GbE NAS testing saw some noticeable variations with the TS-h973AX delivering much higher speeds for our 25GB large file copies. However, Synology was marginally faster when the 25GB file was copied to an encrypted NAS folder and also for our general backup test which involved securing a 22.4GB folder with 10,500 small files.

 

TS-h973AX deuplication results

We found QNAP’s in-line deduplication and compression services can make big storage savings

 

To test Qnap’s deduplication efficacy, we created a share on the TS-h973AX 32GB model with this enabled and copied 121GB of data to it from multiple Windows 10 clients. On completion, we checked the QuTS Storage & Snapshots app report page which showed this has been reduced by over 20% to 96.2GB.

Software comparison

One of the biggest differentiators between NAS vendors is their operating system (OS) as all the best hardware features will be for nothing if the software doesn’t have the features to match. Qnap’s QTS (Qnap Turbo Station) and Synology’s DSM (DiskStation Manager) OSes have always been fairly evenly matched for apps and services but the TS-h973AX is a game changer as it runs Qnap’s new QuTS hero.

 

This OS is based on the 128-bit ZFS (Zettabyte File System) kernel and has a sharper focus on data integrity and protection. End-to-end checksums offer transparent self-healing of data corruption, ZFS copy-on-write provides fast, near unlimited snapshots and you have triple mirroring which stores identical copies of your data on three drives plus triple parity RAID (RAID-TP) to protect against three drive failures.

 

QuTS hero can make big storage savings with its in-line deduplication but bear in mind that this service requires a minimum of 16GB of appliance memory to function. NAS share data can also be protected from unauthorized deletion or modification by applying one of two WORM (write once read many) policies.

 

One point we would highlight about the TS-h973AX is the integral caching features of QuTS hero mean you are only likely to see any improvements to read operations when using NVMe SSDs. Qnap removed write caching from QuTS hero as its ZFS file system’s ARC (adaptive read cache) and ZIL (ZFS intent log) features are already very efficient.

 

TS-h973AX app dashboard

QNAP provides an impressive variety of apps for its QuTS hero operating system

 

Anyone familiar with Qnap’s QTS won’t have any problem using QuTS hero as their web interfaces are virtually identical. There’s no shortage of apps either as we counted 139 available for the TS-h973AX and these include the excellent backup and file syncing apps such as Hybrid Backup Sync (HBS) 3, Qsync Central and HybridMount plus Hyper Data Protector which protects VMware and Hyper-V virtualized environments.

 

Synology can’t match Qnap’s data integrity features but its DSM software does support manual and scheduled snapshots on BTRFS-formatted volumes. It also wins the business backup contest as its free Active Backup Suite can secure servers, workstations plus VMware and Hyper-V virtual hosts from one app with extra ones provided for protecting G Suite and Office 365.

 

Synology DSM software

Synology’s DSM offers a superb set of data protection tools including the Active Backup Suite and Snapshot Replication apps

 

Another DSM app of distinction is Synology’s Surveillance Station which offers a superb range of video monitoring features. It supports nearly 8,000 IP camera models while its video management and recording features are outstanding.

Conclusion

Both the TS-h973AX and DS1621xs+ are hugely capable NAS appliances offering an impressive range of apps and network storage services. Ultimately, your buying decision comes down to what you want the NAS appliance to achieve and your budget.

 

With the 32GB model costing a shade over $1,000, the TS-h973AX is great value and the best choice if you want the wider support for HDDs and SSDs plus dual 2.5GbE multi-Gigabit ports. Its QuTS hero OS is just as easy to use as Qnap’s standard QTS version and it delivers enterprise-class data integrity and protection features.

 

You won’t see any major benefits using U.2 NVMe SSDs for caching as Qnap has removed the write cache from QuTS hero due to the efficiencies already present in the ZFS file system. However, unlike Synology, you can use them to create a separate high-performance storage pool.

 

The DS1621xs+ is more expensive but everything about it exudes quality and it’s much faster than the Atom-powered DS1618+ it’s replacing. Synology’s DSM software is packed with features including the best data backup and surveillance apps making it a great choice for a wide range of businesses. Performance over 10GbE is impeccable, its spare PCI-E slot provides good expansion potential and the icing on the cake is the inclusive 5-year hardware warranty.

And the winner is...

Synology’s DS1621xs+ takes the gold medal as it delivers great all-round performance and superior expansion potential, its DSM software offers a huge range of business-class apps and the price includes a 5-year warranty.
4.5/5
ds1621xsplus-vs.png
9Expert Score
Synology DS1621xs+

The DS1621xs+ is expensive but everything about it exudes quality and it’s faster than the Atom-powered DS1618+ it’s replacing - a lot faster.

Performance
10
Features
9
Build Quality
9
Usability
9
Value
8
Positive
  • Superb performance
  • Embedded 10GbE port
  • Expansion slot
  • M.2 NVMe SSD support
  • Feature-rich DSM software
  • 5-year warranty
Negatives
  • Pricey for a 6-bay NAS appliance
3.5/5
973ax-vs.png
8.2Expert Score
Qnap TS-h973AX

The 32GB TS-h973AX is great value and the best choice if you want the wider support for HDDs and SSDs, dual 2.5GbE multi-Gigabit ports and top-notch data protection features.

Performance
7.5
Features
9
Build Quality
8
Usability
8
Value
8.5
Positive
  • Great value
  • U.2 NVMe SSD support
  • 2.5GbE and 10GbE ports
  • Enterprise-class data protection features
  • Integral deduplication
  • Plenty of app choices
Negatives
  • Caching only boosts read performance
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