
Synology continues to make inroads into the mid-range and enterprise storage markets with an appliance that focuses sharply on performance, on-premises capacity and scalability. Stepping up as the flagship of Synology’s SA series of 2U rackmount NAS models, the 12-bay SA3600 is powered by a 12-core 2.1GHz Xeon D-1567 CPU.
The CPU is the only differentiator between the SA3600 and the SA3400 which impressed us sufficiently for it to earn a coveted Simply.Reviews Top 10 award. The SA3400 is powered by a slightly older 8-core 2.1GHz Xeon D-1541 CPU and Synology is aiming the higher-specified SA3600 at large-scale businesses that have even more demanding workloads.
The SA3600 supports SAS3 and SATA storage devices and its base 16GB of DDR4 ECC memory can be upgraded to 128GB. Combining this with the higher core count makes the SA3600 a better candidate for virtualization duties using Synology’s Virtual Machine Manager (VMM) and Docker apps.

Build quality
The SA3600 employs the same sturdy chassis as the SA3400 which also uses four hot-swap cooling fans. These are easily accessible from a small removable panel in the lid but the SA3600 comes in for the same criticism as their high noise levels keep it limited to the server room.
The front bays support LFF and SSF storage devices which are all managed by a Synology SAS12G PCI-E card. The card presents one external SAS expansion port which supports up to seven RX1217sas or RX2417sas expansion shelves although for essential link redundancy, we would prefer dual SAS ports.
Network options see no changes with the SA3600 offering four embedded Gigabit and two 10GBase-T ports. Two spare PCI-E slots are provided for further expansion with the appliance supporting plenty of industry standard 10GbE and 25GbE adapters.
Top 10GbE performance
To test 10GbE performance, we fitted four 16TB Seagate IronWolf NAS drives in the SA3600 and created a RAID5 storage pool. We added an extra dual-port 10GbE adapter card to the appliance while our test host was a Dell PowerEdge T640 Xeon Scalable server running Windows Server 2019.
Starting with IP SANs, we found a 500GB target mapped over a single 10GbE port returned excellent Iometer read and write rates both of 9.3Gbits/sec. This is the same as we achieved with the SA3400 but we noted appliance CPU utilization was slightly lower at 1% for reads and only 5% for writes.
Moving to a quad 10GbE MPIO link saw read and write speeds ramp up to 36.4Gbits/sec and 18.1Gbits/sec. These were increases over the SA3400 of 0.3% and 0.8% and we noted that CPU utilisation for write operations was 7% lower.
An Iometer block size of 4KB returned random read and write rates of 254,500 IOPS and 12,900 IOPS. These results improved considerably when we add a pair of Samsung SAS3 SSDs as a mirrored read/write cache with throughputs increasing to 275,300 and 76,200 IOPS.
NAS performance is good with a share mapped over 10GbE to the host server delivering sequential read and write rates of 9.3Gbits/sec. For real world testing, we recorded read and write rates of 5.6Gbits/sec and 5Gbits/sec when copying a 25GB file between the server and appliance while a backup up a 22.4GB folder with 10,500 small files averaged 2.6Gbits/sec.
Copying the 25GB test file to an encrypted NAS folder averaged 2.2Gbits/sec with CPU utilization only reaching 5%. Compared with the SA3400, copy speeds were slightly faster while CPU utilization was 2% lower.
Great backup features
Choose BTRFS volumes and you can employ snapshots to protect NAS shares and thin-provisioned iSCSI LUNs. Accessed from the Snapshot Replication and iSCSI Manager apps, you can create schedules that take snapshots as often as every five minutes.
Rollback services are excellent and NAS snapshots can be browsed in the File Station app to restore folders and files. Synology also provides new Storage Console apps for VMware and Windows allowing application-aware iSCSI LUN snapshots to be taken.
The Hyper Backup app covers common appliance data backup requirements while the Drive app provides synchronization services for collaboration and file sharing. The free Active Backup for Business (ABB) app is a winner as it offers agent-based PC and server protection, file-level and bare-metal backup plus local and cloud restore services along with support for VMware and Hyper-V hypervisors for agentless application-consistent VM backups.
Top virtualization services
The SA3600’s extra CPU cores and high memory capacity can be put to good use as Synology’s Virtual Machine Manager (VMM) app allows you to create multiple VMs running just about any OS you want. It’s a cinch to use as we had a Windows Server 2019 VM created from an ISO file in only ten minutes and used the vSwitch service to isolate it on selected network ports.
The VMM dashboard provides a complete overview of all VMs and the app offers some useful features. You can quickly create multiple copies of a VM using the cloning service and if you purchase a VMM Pro license, you can migrate them to other Synology appliances.
VMs are backed up with protection plans which use scheduled snapshots and a choice of retention policies so you can define your own RPO (recovery point objective). Another smart feature is VMM’s ability to link up with the ABB app for disaster recovery and facilities to create on-demand VMs from bare-metal backups.
Conclusion
Businesses looking for a powerful and versatile NAS appliance will find Synology’s SA3600 has a lot to offer. Along with SAS3 and SATA device support, it can be easily expanded to keep up with demand while Synology’s DSM software delivers a wealth of quality features
The price tag of $7,687 for a diskless unit means you’re paying a premium for the higher-spec CPU but our tests show that the SA3600 offers a clear speed advantage over the SA3400 and its extra cores will pay dividends if you’re planning on turning it into a virtualization platform.