Effortless capacity expansion for Synology DiskStation1 solutions on-the-fly.
5-bay 3.5”/2.5” SATA expansion
Easily add 5 additional drive bays to Synology DiskStation1. Supporting both 2.5” and 3.5” SATA drives, DX517 is a flexible solution supporting on-the-fly volume expansion or serving as a local backup destination.
Online volume expansion
Managed from DiskStation Manager on the host NAS, the additional bays in the DX517 are immediately ready to be used once connected. On-the-fly volume expansion ensures that storage and services on the host are not interrupted during volume expansion.
Hot-swappable drive tray design
The hot-swappable drive trays of DX517 allow easy drive installation and replacement without powering down the system. Screwless drive tray design reduces the time needed for system setup.
Dedicated local backup solution
Synology DX517 can be used as a dedicated local backup solution for the Synology DiskStation. When created as a separate volume, the DX517 provides a great backup solution to its local hard disks in case of system failure.
Supports creating volumes across different units
21 series: DS1621xs+ , DS1621+ , DS1821+
20 series: DS1520+, DS920+, DS720+
19 series: DS1819+, DS1019+, DVA3219
18 series: DS1618+, DS918+, DS718+, NVR1218
17 series: DS1817+, DS1817, DS1517+, DS1517
16 series: DS916+, DS716+, DS716+II
15 series: DS1815+, DS1515+, DS1515
Supports creating volumes on a single unit only
16 series:DS216+, DS216+II, NVR216
For more information on the compatibility of each expansion unit, please refer to this article.
Please upgrade to DSM 6.2.1-23824-5 or later version before using it with 15 and 16 series models (excluding DS1515, DS716+, and DS716+II).
To have better performance, we recommend creating storage volumes physically located within the same NAS or Expansion Unit, rather than creating volumes across your NAS and Expansion Unit.
Compatible Drive Type* (See all supported drives)
3.5" SATA HDD
2.5" SATA HDD
2.5" SATA SSD
Maximum Internal Raw Capacity
50 TB (10 TB HDD x 5) (Capacity may vary by RAID types)
Hot Swappable Drive
RAID Management through Synology DSM
Size (Height x Width x Depth)
157 mm x 248 mm x 233 mm
Synchronized with the Synology DiskStation
Power Supply Unit / Adapter
AC Input Power Voltage
100V to 240V AC
50/60 Hz, Single Phase
29.9 W (Access)
2.4 W (HDD Hibernation)
British Thermal Unit
102.02 BTU/hr (Access)
8.19 BTU/hr (HDD Hibernation)
Power consumption is measured when fully loaded with Western Digital 1TB WD10EFRX hard drive(s).
5°C to 40°C (40°F to 104°F)
-10°C to 70°C (15°F to 155°F)
5% to 95% RH
80 mm x 80 mm x 2 pcs
Easy Replacement System Fan
Noise Level Testing Environment: Fully loaded with Seagate 1TB ST31000520AS hard drive(s) in idle; Two G.R.A.S. Type 40AE microphones, each set up at 1 meter away from the Synology NAS front and rear; Background noise: 16.49-17.51 dB(A); Temperature: 24.25-25.75˚C; Humidity: 58.2-61.8%
FCC Class B
CE Class B
BSMI Class B
Applicable Extended Warranty
EW201 - 2 Year Extension
Environment & Packaging
Main Unit X 1
Accessory Pack X 1
AC Power Cord X 1
Expansion Cable: eSATA X 1
Quick Installation Guide X 1
| Stock code || IBSY-DX517|
| Brand || Synology|
| Series || NAS Expansion|
| Model || DX517|
| Type || 5-Bay, For compatible DiskStation models (x17 and newer)|
| ROHS || Y|
| Date added || 20/03/2017|
DX517 Spec Information
| Form Factor / Drive Height || 157x248x233mm|
| Platter size || 3.5"|
| Platter (alternate) || 2.5"|
| Guarantee || 3yr|
| Total Drives || 5|
| Total Drives (alternate) || 5|
| RAID || None|
DX517 Spec Connections
|SATA||SATA 7-pin Discrete with Power||Internal||5|
| Weight (kg) || 8kg|
| Weight (bare) || ?|
| Watts || 29.9W|
| Colour || Black|
Reviews & QuestionsPlease share your opinion or ask a question, about THIS product... You are not logged in - we will not be able to reply directly to your message.
Click Here to Log in!
Alternatively, click here to contact us privately.
Synology NAS Expansion DX517 reviews
What is the maximum storage DX517 NAS can handle?
05/11/2020 | Guest
It is better to ask SPAN for free compatibility checks. But as today you could fill it with 5X 18TB Seagate Ironwolf. This would give you a total raw storage of 90TB
Can I use any drives with this NAS?
04/11/2020 | Guest
Yes, but we would recommend to use WD Red or Seagate Ironwolf. They consume less energy and generate less vibration and noise.
Can I add a 2TB HDD and a 2nd one later with RAID1?
03/11/2020 | Guest
Yes, you can migrate from Basic single disk to RAID 1
Can I upgrade the RAM on this NAS?
02/11/2020 | Guest
Yes, it will work with Samsung, WD or Seagate SSD. In fact this will improve the internal speed and make apps run faster.
Is this enclosure suitable for a SSD - such as Samsung EVO SATA III SSD
01/11/2020 | Guest
Would you like to tell us about a lower price for DX517?Link to a DX517 review page Does what it says. No problems.
28/06/2017 | Harry
Synology DiskStation NAS DS420+ 4-Bay, 2x NVMe (2GB RAM) |
Synology DiskStation NAS DS620slim 6-Bay 2.5" (2GB RAM) |
Synology DiskStation NAS DS420+ (10GB) 4-Bay, 2x NVMe (2GB + 8GB non-Synology RAM) |
Synology RackStation Expansion RX418 for 4-Bay 1U RackStation NAS (no RAIL KIT) - 15, 16, 18, 19, 20 Series |
Synology DiskStation NAS DS720+ (6GB) 2-Bay, 2x NVMe (2GB + 4GB Synology RAM) |