Synology DiskStation DS3615xs Review

DS3615xs FrontSynology’s DS3615xs hauls desktop NAS appliances into the big business space as this 12-bay box delivers a big hardware package. It’s certified to support the latest 6TB drives from Seagate and WD and so offers a maximum capacity of 72TB

There’s more on the menu as Synology has incorporated the high-speed Infiniband ports from its enterprise rack appliances into the DS3615xs allowing it to support a pair of 12-bay DX1215 desktop expansion units. With two of these units connected you can push the drive count to 36 and raw storage capacity to 216TB.

It’s not short on processing power either as it uses a dual-core 3.4GHz Intel Core i3-4130 CPU. This is teamed up with a decent 4GB of DDR3 ECC memory which can be boosted to 32GB although you will need to replace the existing pair of 2GB modules to achieve this.

Build quality

The DS3615xs is well built with a solid metal chassis and two very large and very quiet cooling fans at the rear. The complete fan unit is easily removed but we recommend caution if you need to replace it. As we found out the hard way, the power supply pins in the chassis’ mating connector can easily get bent when re-inserting the fan unit as they don’t match up perfectly.

DS3615xs Rear

The appliance is 10GbE ready as it has an 8X PCI-Express slot which supports Synologys’ adapters and industry standard models from Emulex and Intel. Installation is easy as we only had to remove two screws and the lid to access the slot.

We loaded up an Emulex dual-port OCE11102-NM adapter but found space a little tight at the back. The main problem is the rear of the adapter card sits only a few millimeters above the unprotected metal drive cage.

Excellent 10GbE performance

For 10GbE testing, we used a direct fibre connection with an HP ProLiant DL380 Gen9 rack server. This was equipped with dual 14-core 2.3GHz E5-2695 v3 Xeons, 64GB of DDR4 plus a dual-port Emulex OCE11102-NM adapter and running Windows Server 2012 R2.

NAS speeds are top-notch as a mapped share returned Iometer raw sequential read and write rates of 1,126MB/sec and 1,114MB/sec. This translates well for real world performance as copying our 50GB Iometer file between the appliance and server returned high sustained read and write rates of 430MB/sec and 385MB/sec.

IP SAN performance is marginally faster with a 750GB target delivering Iometer read and write speeds of 1,128MB/sec and 1,126MB/sec. Using dual 10GbE fibre connections, we created an MPIO link and saw read and write speeds ramp up to 1,900MB/sec and 1,715MB/sec – not as fast as Synologys’ claims but impressive nonetheless.

Synology’s DSM 5.1 on the DS3215xs

Synology’s DSM 5.1 offers a remarkable range of features including some quality backup apps

DSM storage features

Using the DSM (Disk Station Manager) web interface, we found storage simple to configure. On first contact it runs through a wizard which offered to download the latest DSM version and create a RAID5 array from our drives.

Synology’s Hybrid RAID (SHR) feature has now been removed so you no longer have the option of creating arrays using drives of different makes and sizes. Nevertheless, data protection options are tops as you also have support for dual-redundant RAID6 arrays.

We had no problems creating IP SANs from the Storage Manager by selecting a volume, choosing a LUN size and enabling thin provisioning. Along with cloning and scheduled LUN snapshots, the advanced LUN feature also activates support for VMware VAAI and Windows ODX data offloading.

SSD read and write caching for volumes and iSCSI LUNs is supported although two identical SSDs are required for write caches. If you opt for a read cache, the appliance creates a stripe from them and for a read/write cache, it’ll create a mirror.

DS3615x Surveillance Station 7.0

Synology’s new Surveillance Station 7.0 is very well designed and provides plenty of monitoring and recording features

Surveillance Station 7.0

One feature of DSM that doesn’t get the coverage it deserves is Synology’s Surveillance Station. We tested v7.0 which is currently in beta and found it to be one of the best examples of this type of application and capable of making good use of the appliance’s massive storage capacity.

Installed as a DSM app, v7.0 has a redesigned interface and we added D-Link IP cameras using the slick auto-discovery process. It supports scheduled recordings and we set our camera to record a 5 minute video clip to the appliance every 30 minutes.

Motion detection is fully supported and we used the new Action Rule feature to apply timed recordings and snapshot schedules to event triggers. Notification options are plentiful as the app can send email alerts for a wide range of conditions including lost camera connections, motion detection triggers or when recording storage has been removed.

DS3215xs Cloud Station

The Cloud Station makes light work of backing up workstations and mobiles to the NAS appliance

Features for all

Synology gets high marks for the range of features offered by its latest DSM 5.1. Its Security Advisor keeps your NAS appliance safe and sound by identifying any weak spots in your configuration, you can enforce 2-step verification for users and choose which network ports can present specific services.

Backup features don’t get any better as the DS3615xs supports replication and shared folder synchronization with other Synology appliances. Extensive cloud backup options include ElephantDrive, Symform, HiDrive, Microsoft Azure, Amazon S3 and the latter’s low-cost Glacier service.

Synology’s Data Replicator backup software gets its marching orders to be replaced by the Cloud Station app which synchronizes files from your PCs and mobiles and between two Synology appliances. And then there’s the Cloud Sync app which supports all manner of cloud services including OneDrive, box, Google Drive and Dropbox plus it’s a cinch to set up.


  • Massive range of features
  • Top 10GbE performance
  • Dual embedded Infiniband ports
  • High expansion for a desktop appliance


  • Tight fit for 10GbE adapters
  • Flawed cooling fan plug design


No other vendor can match the DS3615xs for sheer capacity as this is the biggest desktop NAS appliance on the planet. The two design flaws we found knock its scores down slightly but it grabs them back with its huge range of features, massive expansion potential and excellent 10GbE performance.

8.9 Total Score
Unmatched Capacity

No other vendor can match the DS3615xs for sheer capacity as this is the biggest desktop NAS appliance on the planet. The two design flaws we found knock its scores down slightly but it grabs them back with its huge range of features, massive expansion potential and excellent 10GbE performance.

Build Quality
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