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Synology SA3400 Review

Synology is making eyes at the mid-range and enterprise storage markets as its latest SA3400 storage appliance teams up a wealth of features, great performance and a high expansion potential all offered at a tempting price. This 2U rack NAS supports SAS3 and SATA storage and gets the benefit of an uprated 8-core 2.1GHz Xeon D-1541 CPU.

The SA3400 honours Synology’s 2-year refresh cycle by replacing the RS18017xs+ which was launched back in 2017. Along with a more powerful CPU, the SA3400 comes with faster 2,400MHz DDR4 memory and being the ECC RDIMM variety, the base 16GB can be upgraded to a massive 128GB.

Synology has introduced a new naming convention to differentiate its latest products. The ‘SA’ portion indicates an appliance that supports SAS storage, the ‘34’ means its CPU is performance-oriented, the first zero says it’s the first generation and the last zero just makes up the numbers.

Hardware features

The appliance’s multi-core CPU and big memory capacity are made for Synology’s virtualization app

The SA3400 is well constructed with the 12 hot-swap drive bays at the front supporting SATA III and 12Gbps SAS3 LFF and SFF devices. A removable cover on top reveals four individually hot-swappable cooling fans although their high noise levels make the SA3400 a candidate for a dedicated server room.

Storage is looked after by a Synology SAS12G PCIe card cabled to the hard disk backplane. This also provides one external SAS expansion port for connecting up to seven RX1217sas or RX2417sas expansion shelves.

The SA3400 offers the same four embedded Gigabit and two 10GBase-T ports as the RS18017xs+ while the two free PCIe slots support plenty of industry-standard adapters. The two rear USB 3 ports are for adding external storage where the USB Copy app automates data backup tasks that run when a device is plugged in.

Deployment and backup features

We saw an impressive performance over a quad 10GbE MPIO link to an iSCSI target

Synology’s discovery web portal makes light work of deployment as it found the appliance on the lab network and downloaded the latest DSM 6.2 software. We fitted four of Seagate’s latest enterprise-class 16TB Exos X16 SATA hard disks and used the Storage Manager app to create a 44TB RAID5 storage pool.

The SA3400 is perfect for backup duties as DSM offers a wealth of free apps. The star player is Synology’s Active Backup suite which offers apps for securing servers, workstations and virtualized environments along with G Suite and Office 365.

The Active Backup for Business (ABB) app provides agent-based PC and server protection along with file-level and bare-metal backup plus local and cloud restore services. It supports VMware vCentre and ESXi hypervisors for agentless application-consistent backups of virtual machines (VMs).

The Snapshot Replication app manages NAS and IP SAN snapshots on BTRFS volumes and offers fast rollback services along with NAS share file and folder recovery using the File Station app. Local, remote, Rsync, cloud and iSCSI LUN backups are looked after by the Hyper Backup app while the Drive app provides synchronization services for collaboration and file sharing.

Virtualization features

Synology’s Virtual Machine Manager (VMM) app allows the SA3400 to host VMs running any OS you choose. The appliance’s base 16GB of memory is easily enough to get you started while the maximum of 128GB is plenty for hosting multiple VMs.

The app is simple to use and we created a Windows Server 2019 VM, installed it from an ISO file and had it running in 15 minutes. The VMM dashboard provides quick access to VMs and the vSwitch service can isolate them on specific network ports.

Protection plans are used to backup selected VMs using snapshots and can be run to a schedule with a retention policy for a specific RPO (recovery point objective). The VM cloning feature can create multiple identical copies of VMs and also migrate them to another Synology appliance running the VMM app, although this requires an optional VMM Pro license.

VMM also links up with the ABB app to provide smart disaster recovery features. From the ABB console, you can select a bare-metal or VMware VM backup and instruct it to create an on-demand VM.

Super 10GbE performance

Adding an SSD cache can bring a big speed boost to random write operations

The SA3400 delivers on its performance promises. With a NAS share mapped over 10GbE to a Dell PowerEdge T640 Xeon Scalable host running Windows Server 2019, we recorded top Iometer sequential read and write rates of 9.3Gbits/sec.

Real world speeds are equally good with copies of a 25GB test file returning read and write rates of 5.6Gbits/sec and 5Gbits/sec. A backup of our 22.4GB folder and its 10,500 small files averaged 2.5Gbits/sec while copying the 25GB test file to an encrypted folder mustered a creditable 2Gbits/sec with CPU utilization only reaching 7%.

The SA3400 is a great choice for deploying high-performance IP SANs as a 500GB target returned top Iometer read and write rates both of 9.3Gbits/sec. After adding a dual-port Emulex 10GBaseT adapter in the appliance, we created a quad 10GbE MPIO link to the target and saw read and write speeds increase to 36.1Gbits/sec and 17.3Gbits/sec.

Using 4KB Iometer block sizes, we recorded random read and write rates for the quad MPIO target of 252,500 IOPS and 12,000 IOPS. The latter figure was improved significantly when we assigned a dual SSD read/write cache to the volume as random write performance increased to 49,500 IOPS.


A close competitor to the SA3400 is Qnap’s 12-bay TVS-EC1280U-SAS-RP R2. However, although the latter is cheaper by around $800, it’s now showing its age as it employs a 6-year-old Xeon E3-1245 v3 CPU which only supports up to 32GB of slow DDR3 UDIMM memory.

The SA3400 delivers a powerful storage package which returned impressive 10GbE performance results in our lab tests. Add in its high expansion potential and feature-packed DSM software and you have an enterprise-class storage solution at an SME price.

8.9 Total Score
Powerful Storage Package

The SA3400 delivers a powerful storage package which returned impressive 10GbE performance results in our lab tests. Add in its high expansion potential and feature-packed DSM software and you have an enterprise-class storage solution at an SME price.

Build quality
  • Good overall value
  • Superb performance
  • SAS3/SATA support
  • Feature-rich DSM 6.2
  • Great range of free backup apps
  • Single SAS expansion port
  • High noise levels from cooling fans

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