Qnap TS-451U

TS-451UQNAP’s new TS-451U heads up its entry-level family of NAS appliances and targets small businesses and SOHOs on a tight budget. And with a price tag of only $899 for a diskless unit, it looks like an excellent value.

There are few compromises in QNAP’s search for value as this compact 1U rack mount unit packs in an impressive range of features. The hardware specification is pretty good, too.

The TS-451U sports a dual-core 2.41GHz J1800 Celeron CPU while its 1GB of low-voltage DDR3L memory can be boosted to 8GB. This is easily achieved as the lid is held on by six screws and the motherboard has a secondary SO-DIMM socket ready and waiting.

The appliance provides four hot-swap drive bays and is certified to support 6TB drives from Toshiba, WD and Seagate. You can also attach one of QNAP’s 8-bay or 12-bay UX rack mount expansion enclosures over a USB 3 cable link.

Hardware and build quality

The metal chassis is solidly constructed and the lockable drive carriers are metal as well. The appliance has an LED display above the bays showing installed drives and activity, system status plus network activity.

TS-451UDual Gigabit ports are at the rear along with a quartet of USB 3 ports. As you’d expect, this little appliance doesn’t have room to add network upgrade cards.

The USB 2 port at the front could prove handy as you can link it up with backup jobs. When you insert a USB storage device or camera and press the Copy button on the front panel, the new Smart Import feature automatically copies all photos and videos to a local folder.

To fit the appliance in a rack cabinet, you’ll need QNAP’s optional Rail-C01 kit which is expensive at $99. Our only other issue is with the two small cooling fans behind the motherboard. Noise levels aren’t excessive but will be very noticeable in a quiet home or small office environment.

A good performance

For speed testing, we loaded up a quartet of 4TB WD Red hard disks and created a RAID-5 array. This took over eight hours to initialize although we could still use the appliance during this phase albeit with a slightly reduced performance.

The Celeron posted some good times in our tests with drag and drop copies of a 50GB file returning sustained read and write speeds of 112MB/sec. It had no problems with our general backup test as copying our 22.4GB folder with 10,500 small files to a share returned a respectable average of 82MB/sec.

To test maximum performance we used two Xeon E5-2600 v3 servers connected to separate shares on the RAID-5 volume over dedicated Gigabit connections. With Iometer running on each server, we saw it report cumulative read and write speeds of 226MB/sec and 222MB/sec with appliance CPU utilization never going above 45%.

Deployment and storage features

QNAP's Cloud Portal

Qnap’s cloud portal aids installation and sets up the appliance’s hard disks for you.

With QNAP’s cloud portal on the case, deployment is a cinch. We entered the unique code on the appliance’s lid, registered the appliance with our myQNAP cloud account and left it to create our RAID-5 array.

When you use the quick start portal it automatically creates a single volume from selected drives but if you want fast block-based iSCSI targets you’ll want to side-step this. The main benefits of volumes are they support file-based targets with thin provisioning plus LUN backup and snapshots.

A storage pool supports block-based targets but another key feature is its ability to aggregate hard disks into a single storage space. Within this you can create multiple RAID volumes for shares and iSCSI LUNs and dynamically expand the pool into new hard disks.

Another thing to consider is QNAP only supports volume encryption whereas Synology lets you do this at the share level. However, as you can create multiple volumes within QNAP’s storage pools, you can decide which ones you want encrypted.

We used Qnap's RTRR backup tool to replicate our 2-bay NAS appliance to the TS-451U.

We used QNAP’s RTRR backup tool to replicate our 2-bay NAS appliance to the TS-451U.

Replication and backup

The RTRR (real time remote replication) feature makes the TS-451U a handy repository for backing up other QNAP appliances to. We found it very easy to use as from the Backup Station app on the TS-451U, we enabled the RTRR server, set password protection and created a list of remote devices that could access it.

For our remote client, we used a little TS-269L 2-bay appliance and from its Backup Station, created a replication job which linked a local folder with the target folder on the TS-451U. We opted for real-time replication, selected the SSL connection option and left the job to keep the two folders in sync.

The scheduled replication option allowed us to select hourly, daily, weekly or monthly intervals. We could also add extra folder pairs to the same job, set bandwidth usage limits on either side of the RTRR link and add file type and size filters.

The QTS interface is intuitive

The QTS interface is intuitive and the new Smart Import feature backs up photos and videos on memory sticks and cameras.


We’re not convinced it has any value on a rack mount appliance but QNAP’s QvPC technology lets you access the TS-451U with a locally attached HDMI monitor, mouse and keyboard. You can watch video, radio or TV feeds, browse the web and access the main QTS web console.
The latter is required to use the appliance as a PC as you load the Virtualization Station from the local QTS console, select a VM and control its OS directly. Don’t forget the Virtualization Station requires a minimum of 2GB of memory to run so you must upgrade the TS-451U to use it.


  • Very good value
  • Fast performance
  • Feature packed QTS software
  • Remote replication and backup tools


  • Cooling fans a little noisy for a small office
  • Virtualization Station will need a memory upgrade


The TS-451U teams up an impressive range of features with plenty of storage capacity and room to grow. Overall performance is good, the QTS software offers excellent backup and replication utilities and it’s very good value as well.

8.4 Total Score
Good Value

The TS-451U teams up an impressive range of features with plenty of storage capacity and room to grow. Overall performance is good, the QTS software offers excellent backup and replication utilities and it's very good value as well.

Build Quality

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