Thecus N4910U Pro-S Review

Thecus’ latest rack NAS is designed to offer SMBs a versatile network storage solution with plenty of power under the hood for demanding workloads. It certainly scores on the last count as this compact 1U rack mounter is endowed with a 3.3GHz E3-1225 v5 Xeon CPU partnered by a generous 8GB of DDR4 memory.

Thecus supplied our system with a pair of 4GB sticks but if you feel the need for more speed, you can upgrade it to the maximum 64GB. Standard ports include dual Gigabit and four USB 3 plus USB 2 while a spare PCI-Express slot is available for 10GbE upgrades (we’ll come to this later).

The appliance supports up to four SATA hard disks or SSDs and it’s certified for the latest 10TB models from Toshiba, Seagate and Western Digital. The model on review is the single 250W fixed PSU version and Thecus also offers a N4910U Pro-R version which has dual 300W redundant PSUs.

Design flaws

Choosing BTRFS during RAID array creation enables NAS share and IP SAN snapshots

There’s no denying Thecus’ build quality as this appliance is built like a tank with a solid steel chassis and lid. At the front is an equally sturdy flip-down cover complete with backlit LCD status display and behind this are the hot–swap drive bays along with power controls and status LEDs.

All looked fine under the lid until we tried to add a 10GbE adapter as we hit a major problem. The PCI-Express slot is located at the rear on the left but vertical space is severely restricted due to the position of the motherboard’s USB and COM1 connectors.

The cables for these sockets plug in vertically and stop any adapter card with a heatsink from being fitted. We tried Emulex OneConnect OCE11102-NM and Intel X520-SR2 10GbE adapters both with passive heatsinks and an Emulex OneConnect OCE11102-NT with an active heatsink and all were blocked by the cable connectors.

The bottom line is to ignore Thecus’ adapter compatibility chart as it states these cards are compatible with N4910U models. If you want to upgrade the appliance, we recommend only using low-profile adapters that don’t have a heatsink.

The other issue is noise as with the fan control set to automatic, we recorded an annoying 64dB from one meter in front of the appliance. As long as you only fit 5,400rpm drives, you can select the low speed setting which dropped our reading to 59dB.

Gigabit performance

The good news is the appliance delivers fast speeds over Gigabit and for testing, we fitted four 8TB Seagate NAS HDD drives and created a RAID5 array from the slick ThecusOS7 web interface. Our host system was a Lenovo ThinkSystem SR650 equipped with dual Xeon Silver 4110 CPUs and running Windows Server 2016.

With a share mapped to the server, we saw Iometer record top sequential read and write speeds both of 113MB/sec. Real world speeds were on a par as our 25GB file copy averaged read and writes of 113MB/sec and 112MB/sec.

Thecus also handled our backup test well with a 22.4GB folder containing 10,500 small files secured to a share at a speedy 89MB/sec. IP SAN performance was equally good with a 500GB target also returning Iometer read and write speeds of 113MB/sec.

ThecusOS 7

The N4910U Pro comes preinstalled with the latest ThecusOS 7 firmware which adds plenty of new features. The freshly designed web interface is more intuitive and easier on the eye plus it offers a desktop space that can display custom backgrounds along with quick access icons for your favourite apps.

The Disk & RAID app makes light work of storage configuration and provides easy access for creating NAS shares and IP SAN targets. Access security is good as the appliance can apply a local user database or integrate with external Active Directory or LDAP authentication and apply per-user quotas to control storage usage.

The Disk Clone feature creates multiple copies of source drives and has a handy security wipe option. Appliance storage capacity can’t be physically expanded to external disk shelves but the Scale Out feature allows you to create larger volumes by combining RAID arrays from multiple Thecus appliances.

Data protection and clouds

Choosing BTRFS when creating a RAID array brings NAS and IP SAN snapshots into play where they can be run on demand and scheduled at regular hourly, daily, weekly or monthly intervals. Recovery is more basic as you select a snapshot from the list and simply apply it – Qnap allows you browse snapshot contents and choose a single file.

Thecus provides a good range of backup services and supports real-time and scheduled backups of NAS shares and iSCSI LUNs to local storage, external USB devices and remote NAS appliances via Rsync. You can also set the front USB port to copy the contents of an inserted device to a selected folder when the button on the panel is pressed.

App choices have improved significantly and they can be browsed and loaded directly from the new App Center. They aren’t as copious as those offered by Qnap or Synology but you do get ones for file syncing to Dropbox, ElephantDrive, OneDrive and Google Drive plus an option in the Control Panel for backing up data to Amazon S3 cloud buckets.

Thecus no longer includes the free Intel AntiVirus app but you can use the ClamAV version instead. The package also includes a 5-user licensed copy of Acronis True Image Personal 2015 which provides some handy workstation backup tools.


As a simple NAS and IP SAN appliance, the N4910U Pro works well and its Xeon E3 v5 CPU has plenty of power on tap for SMBs with heavier workloads. We are distinctly unimpressed by the poor internal design that limits its 10GbE upgrade potential but if this isn’t an issue you’ll find this powerful 1U rack appliance an affordable option.

  • Solid build quality
  • Xeon E3 v5 CPU
  • ThecusOS7 firmware
  • Good backup features
  • Powerful spec for the price
  • Poor internal design limits 10GbE upgrades
  • Noisy cooling fans

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