| CPU | Intel 4-core processor |
| CPU Architecture | 64-bit x86 |
| Floating Point Unit | Yes |
| Encryption Engine | Yes (AES-NI) |
| Hardware-accelerated Transcoding | Yes |
| System Memory | 8 GB SODIMM DDR5 |
| Maximum Memory | 16 GB (1 x 16GB) |
| Memory Slot | 1 x SODIMM DDR5 |
| Flash Memory | 4GB (Dual boot OS protection) |
| Drive Bay | Front: 4 x 3.5-inch Rear:2 x E1.S/M.2 NVMe Gen3 x1 slots |
| Drive Compatibility | 3.5-inch bays: 3.5-inch SATA hard disk drives 2.5-inch SATA solid state drives E1.S/M.2 slots: |
| Hot-swappable | Yes |
| M.2 Slot | Optional via a PCIe adapter |
| SSD Cache Acceleration Support | Yes |
| 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 network adaptor |
| 10 Gigabit Ethernet Port | Optional via network adaptor
Optional via PCIe expansion card
|
| Wake on LAN (WOL) | Yes |
| Jumbo Frame | Yes |
| PCIe Slot | 1 x PCIe Gen3 x2
Slot 1: PCIe Gen 3 x2 |
| USB 2.0 port | 3 |
| USB 3.2 Gen 2 (10Gbps) Port | 1 x Type A USB 3.2 Gen 2 |
| Form Factor | 1U Rackmount |
| LED Indicators | HDD 1-4, E1.S/M.2 1~2, Status, LAN, Expansion, Power |
| Buttons | Power, Reset |
| 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, 100-240V |
| System Warning | Buzzer |
| Standard Warranty | 3 |
| Max. Number of Concurrent Connections (CIFS) – with Max. Memory | 1500 |
TS-h665U
TS-h665U is designed for small and medium-sized businesses, powered by an Intel® quad-core processor, and equipped with dual 2.5GbE network ports that support port trunking for up to 5 Gbps network bandwidth. A PCIe expansion slot allows flexible upgrades, such as adding a 10GbE/5GbE network card or a QM2 card for M.2 SSD caching, delivering exceptional expandability. With the built-in Intel® AES-NI encryption engine, TS-h665U maintains outstanding data access performance even when accelerating AES 256-bit encryption.
Within a 1U chassis, TS-h665U offers four 3.5-inch SATA bays and two high-expandability E1.S slots, delivering a powerful and efficient multitasking NAS solution. TS-h665U comes with the QuTS operating system preinstalled, offering ZFS data integrity and immutability to protect against data tampering






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Dual 2.5GbE as standard
Accelerate data transfer and backup speeds by enabling Port Trunking or SMB Multichannel.
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DDR5 RAM
Built-in high-performance and low power consumption DDR5 RAM supports In-Band ECC (IBECC) for data reliability. Up to 16GB RAM can be installed.
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Flexible E1.S slots
E1.S NVMe PCIe slots provide flexible configuration of SSD caching, ensuring the NAS is never limited in its specifications.
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Secure Snapshot Protection
Snapshots record the complete system state and data, allowing you to quickly restore the system to a normal state in the event of unexpected incidents.
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PCIe Gen 3 slot
Supports 5/10GbE NIC or QM2 expansion cards, offering flexible upgrades for high-speed networking and enhanced application performance.
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Long-term supply
TS-h665U will be available and supported by QNAP for an extended period, up to 2031.

QuTS hero Operating System
Honored with 2026 MSP Today Product of the Year Award
New-gen high-performance Intel® Quad-core processor
| 2 x 2.5GbE SMB sequential throughput (1M) | Read
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Write
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|---|---|---|
| 2 x 10GbE SMB sequential throughput (1M) | Read
NaNNaN MB/s
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Write
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Tested in QNAP Labs. Figures may vary by environment.
Test Environment:
NAS: TS-h665U with QXG-10G2TB
OS: QTS 5.2.6.3209
Volume type : 8 x Samsung 870 EVO 1TB SATA SSD , RAID 5, thick volume
Client PC : Windows Server 2019 Standard, Intel i7-6700 3.4GHz, 64GB RAM, LAN-10G2T-X550
IOmeter : RAM*4, 30-sec ramp up time, 3-min seq. run time, 1 workers, 32-outstanding
Surpass the competitor with standard 2.5GbE and flexible 10GbE upgrade
In modern business IT, a NAS with only 1GbE is a performance bottleneck. The TS-h665U comes with faster network connectivity which enables businesses to facilitate bandwidth-demanding applications, such as large file access, backup/restore, virtualization, and more.
Powerful expansion with E1.S PCIe slots
TS-h665U has two E1.S NVMe slots that offer unparalleled NAS flexibility for boosting performance.
Abundant I/O capabilities with PCIe expansion
TS-h665U has one PCIe Gen 3 x2 slot that allow for installing various expansion cards for expanding application potential.
Future-proof your storage with JBOD scalability
All-in-one backup solution
The TS-h665U supports various apps that cover all your backup needs. See all
Real-time sync for seamless team collaboration
Whether you’re in the office or on the go, you can access the latest files synchronized to TS-h665U on multiple devices for efficient teamwork. Version Control keeps track of document changes, simplifying file management and restoration.
Multi-level security strategy for enterprises
Bolster business data security with resilience from all aspects
Run VMs and Containers
With no additional fees, you can run multiple VMs of different OS on TS-h665U. This allows you to deploy multi-tenant environments and applications to increase management efficiency and save hardware costs.
Surveillance NAS solution for Business
Surveillance NAS is an easy-to-deploy and cost-efficient all-in-one intelligent surveillance platform that integrates AI analytics, video backup and fault tolerance, centralized management (CMS), and surveillance cloud services, meeting professional surveillance requirements across diverse deployment scenarios. A single NAS supports up to 1,024 channels, leveraging file-based writing technology to enhance processing performance and meet the demands of multi-channel, high-capacity, and long-duration recording. Learn more about QVR Surveillance NAS solution
QNAP solves all your surveillance system challenges in business
Use AI-powered drive failure prediction to safeguard your data
Switch to QuTS hero operating system
for optimal data integrity and reliability
Extend hardware warranty up to 5 years
The TS-h665U is backed by a 3-year warranty at no additional cost.
You can also purchase a warranty extension that extends your warranty coverage up to 5 years.




























