8-Bay 2U Short-Depth Rackmount NAS
QNAP TS-855EU-8G Short-Depth Rackmount NAS
An eight-bay short-depth rackmount NAS with an Intel Atom C5125 eight-core processor, 8 GB DDR4 memory, dual 2.5GbE, two M.2 NVMe slots and two PCIe Gen 3 slots.
Expandable eight-bay storage in a compact rack chassis
The QNAP TS-855EU-8G combines an eight-bay storage layout with a 297.4 mm-deep 2U chassis for compact rack installations. Dual M.2 NVMe slots, two PCIe Gen 3 slots, dual 2.5GbE and support for virtual machines and containers provide room to adapt the system for business storage, backup and application hosting.
Key features and benefits
Space-saving rack design
A depth of 297.4 mm helps the NAS fit compact racks and cable-dense installations.
Eight SATA drive bays
Eight hot-swappable SATA bays provide a practical base for centralised business storage.
NVMe storage options
Two M.2 2280 PCIe Gen 3 x4 slots support compatible NVMe SSDs for caching or storage pools.
Flexible PCIe expansion
Two PCIe Gen 3 x4 slots accept compatible network, QM2 or Fibre Channel cards.
Dual 2.5GbE ports
Two multi-gigabit RJ45 ports support fast file access and port trunking.
Long-term platform planning
The description states that the model will remain available and supported up to 2030.
Who is this model best for?
A strong choice for
- Compact business rack installations
- File serving and backup workflows
- Virtual machines and containerised applications
- Teams planning staged network or storage expansion
- Long-term deployments requiring matching NAS models
Consider another model if you need
- You require redundant power supplies
- You need built-in 10GbE
- You prefer a desktop tower form factor
Key specifications
- Processor
- Intel Atom C5125, 8-core 2.8 GHz
- System memory
- 8 GB non-ECC SODIMM DDR4 (1 × 8 GB)
- Maximum memory
- 64 GB (2 × 32 GB)
- Drive bays
- 8 × 3.5-inch SATA 6Gb/s, 3Gb/s
- Drive compatibility
- 3.5-inch SATA HDD; 2.5-inch SATA HDD; 2.5-inch SATA SSD
- M.2 slots
- 2 × M.2 2280 PCIe Gen 3 x4
- Networking
- 2 × 2.5GbE RJ45
- Expansion
- 2 × PCIe Gen 3 x4 slots
- Dimensions
- 88.6 × 432 × 297.4 mm
- Power supply
- 250W, 100–240V
Full technical specifications
Processor, memory and storage
| CPU | Intel ® Atom® C5125 8-core processor, 2.8GHz |
|---|---|
| CPU Architecture | 64-bit x86 |
| Floating Point Unit | Supported |
| Encryption Engine | Supported (AES-NI) |
| System Memory | 8 GB non-ECC SODIMM DDR4 (1 x 8 GB) |
| Maximum Memory | 64 GB ( 2 x 32 GB) |
| Memory Slot | 2 x SODIMM DDR4 Support ECC memory For dual-DIMM configuration, you must use a pair of identical DDR4 modules. |
| Flash Memory | 5GB (Dual boot OS protection) |
| Drive Bay | 8 x 3.5-inch SATA 6Gb/s, 3Gb/s The system is shipped without HDD. |
| Drive Compatibility | 3.5-inch SATA hard disk drives 2.5-inch SATA hard disk drives 2.5-inch SATA solid state drives |
| Hot-swappable | Supported |
| M.2 Slot | 2 x M.2 2280 (PCIe Gen 3 x 4) Compatible with NVMe SSD PCIe Gen 3 and above. |
| SSD Cache Acceleration Support | Supported |
| SR-IOV | Supported |
| Max. Number of Concurrent Connections (CIFS) - with Max. Memory | 2500 |
Network, ports and expansion
| 2.5 Gigabit Ethernet Port (2.5G/1G/100M) | 2 (2.5G/1G/100M/10M) |
|---|---|
| 5 Gigabit Ethernet Port (5G/2.5G/1G/100M) | Optional via a network adapter |
| 10 Gigabit Ethernet Port | Optional via a network adapter |
| 25 Gigabit Ethernet Port | Optional via a network adapter |
| Wake on LAN (WOL) | Supported Only the 2.5GbE port |
| Jumbo Frame | Supported |
| PCIe Slot | 2 x PCIe Gen3 (x4) Slot 1: PCIe Gen 3 (x4) Slot 2: PCIe Gen 3 (x4) Card dimensions for PCIe slot 1:97 x 68.9x 18.76 mm / 3.82 x 2.71 x 0.74 inches. Card dimensions for PCIe slot 2:210 x 68.9 x 18.76 mm / 8.27 x 2.71 x 0.74 inches. |
| USB 3.2 Gen 1 port | 4 |
| HDMI™ Output | Optional via a PCIe graphics card |
Physical, environmental and power
| Form Factor | 2U Short Depth Rackmount |
|---|---|
| LED Indicators | HDD 1-8, Status, LAN, USB, Power |
| Buttons | Power, Reset |
| Dimensions (HxWxD) | 88.6 × 432 × 297.4 mm |
| Weight (Net) | 8.1 kg |
| Weight (Gross) | 9.6 kg |
| Operating Temperature | 0 - 40 °C (32°F - 104°F) |
| Storage Temperature | -20 - 70°C (-4°F - 158°F) |
| Relative Humidity | 5-95% RH non-condensing, wet bulb: 27°C (80.6°F) |
| Power Supply Unit | 250W PSU, 100 - 240V |
| Power Consumption: HDD Sleep Mode | 49.799 W |
| Power Consumption: Operating Mode, Typical | 79.113 W Tested fully populated with WD10EFRX hard drives. |
| Fan | 3 x 60mm, 12VDC |
| System Warning | Buzzer |
Frequently asked questions about the TS-855EU-8G
What is the QNAP TS-855EU-8G?
It is an eight-bay 2U short-depth rackmount NAS with dual 2.5GbE, two M.2 NVMe slots and two PCIe expansion slots.
Which processor does the TS-855EU-8G use?
The TS-855EU-8G uses an Intel Atom C5125 eight-core 2.8 GHz processor.
How much memory is included with the TS-855EU-8G?
The TS-855EU-8G includes 8 GB non-ECC SODIMM DDR4 memory as one 8 GB module, with a stated maximum of 64 GB.
How many drive bays does the TS-855EU-8G have?
It has eight 3.5-inch SATA 6Gb/s, 3Gb/s drive bays.
Which drive types are supported by the TS-855EU-8G?
It supports 3.5-inch SATA HDDs, 2.5-inch SATA HDDs and 2.5-inch SATA SSDs.
Which network ports are built into the TS-855EU-8G?
It includes two 2.5GbE RJ45 ports; faster network speeds are optional through compatible adapters.
What expansion options does the TS-855EU-8G provide?
It provides two M.2 2280 PCIe Gen 3 x4 slots and two PCIe Gen 3 x4 expansion slots.
What form factor is the TS-855EU-8G?
It is a 2U short-depth rackmount NAS with a single 250W power supply.
What are the dimensions of the TS-855EU-8G?
Its stated dimensions are 88.6 × 432 × 297.4 mm.
Can the TS-855EU-8G use QuTS hero?
Yes. The product description states that it runs QTS as standard and can be switched to the ZFS-based QuTS hero operating system.
Important information
The system is shipped without hard drives.
The stated 79.113 W operating figure was tested with WD10EFRX drives fully populated.
Check drive, M.2 SSD, expansion-card and JBOD compatibility before purchase.
