TS-251B-20TB

Two‑bay NAS powered by an Intel Celeron J3355 with 4 GB DDR3L, delivering up to 20 TB of SATA storage in RAID 0/1 or JBOD. It features HDMI output, a single speaker, USB backup, iTunes and FTP servers, VPN support, and AES‑256 encryption for secure data handling.

Brand: QNAP
Model: TS-251B-4G/20TB-ULTRA
MPN: TS-251B-4G/20TB-ULTRA
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3.5 mm out Yes
AC input voltage 100 - 240 V
Access Control List ACL Yes
Backup features USB drive
Backup function Yes
Bad block scan Yes
Browser supported Apple Safari 7 or later, Google Chrome, Microsoft Internet Explorer 10 or later, Mozilla Firefox
Built-in display No
Built-in FTP server Yes
Built-in iTunes server Yes
Built-in speakers Yes
Builtin speakers 1
Buzzer Yes
Cable lock slot Yes
Cable Lock Slot Yes
Cable lock slot type Kensington
Cables included AC,LAN (RJ-45)
Chassis type Tower
Colour White
Conflict free processor Yes
Cooling type Active
Depth 226 mm
Device class Home & Home Office
DHCP client Yes
DHCP Client Yes
DHCP server Yes
Dynamic DNS DDNS Yes
ECC supported by processor No
Embedded options available No
Enhanced intel speedstep technology Yes
Ethernet LAN Yes
Ethernet LAN data rates 10,100,1000 Mbit/s
Execute disable bit Yes
Execution units 12
External power adapter Yes
Fan diameter 7 cm
Flash memory 4096 MB
Height 168 mm
Hot spare Yes
Hot-swap drive bays Yes
Idle states Yes
Installed storage drive type HDD
Intel 64 Yes
Intel clear video technology Yes
Intel enhanced halt state Yes
Intel rapid storage technology No
Intel secure boot Yes
Intel Secure Boot Yes
Intel smart connect technology No
Intel Stable Image Platform Program No
Intel trusted execution technology No
Intel Virtualization Technology Yes
Intel Virtualization Technology for Directed I/O Yes
Intel VT-x with Extended Page Tables Yes
Intel® AES New instructions Yes
Intel® Anti-Theft Technology No
Intel® Clear Video HD Technology Yes
Intel® Clear Video Technology for Mobile Internet Devices Yes
Intel® High Definition Audio Yes
Intel® Hyper Threading Technology No
Intel® Identity Protection Technology Yes
Intel® Insider™ No
Intel® InTru™ 3D Technology No
Intel® OS Guard No
Intel® Quick Sync Video Technology Yes
Intel® Secure Key Yes
Intel® Small Business Advantage No
Intel® Smart Response Technology No
Intel® Turbo Boost Technology No
Intel® Wireless Display No
Internal memory 4 GB
Internal memory type DDR3L
iSCSI support Yes
Jumbo frames support Yes
LED indicators HDD,LAN,Power,Status,USB
Linux operating systems supported Yes
Management protocols SNMP
Maximum internal memory supported by processor 8 GB
Maximum number of PCI Express lanes 6
Memory channels supported by processor Dual
Memory slots 2
Memory types supported by processor DDR3L,LPDDR3-SDRAM,LPDDR4-SDRAM
Microphone in Yes
Multilingual support Yes
Noise level 17.3 dB
On-board graphics adapter base frequency 250 MHz
On-board graphics adapter burst frequency 700 MHz
On-board graphics adapter model Intel® HD Graphics 500
On/off switch Yes
Operating system installed QNAP Turbo System
Operating system version 4.3.4
PCI Express configurations 1x2+2x1,4x1
PCI Express slots version 2.0
Power supply location External
Power supply unit PSU capacity 65 W
Processor ARK ID 95597
Processor cache type Smart Cache
Processor code SR2Z8
Processor codename Apollo Lake
Processor family Intel® Celeron®
Processor frequency 2.00 GHz
Processor lithography 14 nm
Processor model J3355
Processor operating modes 64-bit
Processor package size 24 x 31 mm
Processor socket BGA 1296
Quick installation guide Yes
RAID levels 0, 1, JBOD
RAID Support Yes
RAID support Yes
Reset button Yes
Security algorithms 256-bit AES,FIPS 140-2,HTTPS,SSH,SSL/TLS
Share folder CIFS/SMB
Share folder access right management Yes
Storage drive sizes supported 2.5,3.5"
Storage drives installed Yes
Supported file systems FAT32,HFS+,NTFS,exFAT,ext3,ext4
Supported storage drive interfaces Serial ATA III
Supported storage drive types HDD,SSD
System bus rate 5 GT/s
System log Yes
Thermal design power 10 W
Thermal monitoring technologies Yes
Tjunction 105 °C
Type NAS
UART Yes
Universal Plug and Play UPnP Yes
USB port Yes
Wake-on-LAN ready Yes
Wi-Fi No
Windows operating systems supported Windows 10,Windows 7,Windows 8