by Lyle Smith

TerraMaster F2-221 Review

The TerraMaster F2-221 is a 2-Bay NAS designed for small businesses and the home use such as personal cloud and back up. It is compatible with both 3.5 and 2.5 inch HDDs as well as 2.5 inch SATA SSDs with a maximum capacity of a generous 28TB via two 14GB drives. It also features two USB 3.0 ports and two gigabit LAN ports. 

As far as its internal components go, the F2-221 is powered by an Intel dual-core processor (Intel Celeron J3355) with a frequency of up to 2.0 GHz and can be outfitted with up to 8GB of RAM. The F2-221 is expected to reach the usual performance from NAS solutions of this class, quoting read speeds of 215MB/s and a write speeds up to 212 MB/s. The new TerraMaster NAS also supports 4K HD video transcoding for home entertainment use cases.

TerraMaster NAS solutions feature what they call their '5-layer data security protection,' which includes mostly the usual peace-of-mind suspects: automatic scheduled backups, btrfs filesystem and snapshots, RAID 1 array security, AES hardware folder and network transport encryption, and cloud drive backup.

The TerraMaster  F2-221 comes with a 2-year warranty starts at roughly $250 for the diskless, 2GB RAM model.

TerraMaster F2-221 Specifications

Processor model Intel Celeron J3355
Processor architecture 64-bit
Processor frequency Dual Core, 2.0GHz (Maximum Turbo: 2.5GHz)
System memory (standard) 2GB 
Maximum supported memory 8GB
Compatible disk types
  • 3.5" SATA HDD
  • 2.5" SATA HDD
  • 2.5" SATA SSD
Maximum internal storage capacity 28TB (14 TB drive x 2) (Capacity will vary along with the RAID type)
Disk hot plugs Yes
External Ports  
  • RJ-45 1GbE network jack: 2
  • USB 3.0 port: 2
File System
  • Internal disk:EXT4,BTRFS
  • External disk: EXT3, EXT4, NTFS, FAT32, HFS+
Size (H*W*D) 227(H) x 119(W) x 133(D) mm
  • Net Weight: 1.46Kg 
  • Gross Weight: 2.57Kg
System fan 80 mm x 80 mm x25mm  1 pcs
Noise level  18.6dB(A) 
Warranty 2-years


Design and build

The TerraMaster F2-221 is a compact NAS comprised of a silver chassis. The two bays are easily accessed on the front panel. Simply pull the tabs by the bottom and they come right out. 

On the left side of the front are the hard drive and network indicators as well as the power switch. Turning the NAS around reveals all the connectivity, including two USB 3.0 ports, two RJ-45 1GbE network ports, and the power interface, all of which reside next to the fan.


The TerraMaster F2-221 leverages the company's TOS operating system. TOS is a fairly simple GUI. On the left of the main screen are the primary applications such as File Manager, Applications, Recycle Bin, Control Panel, Backup, Remote Access, and TOS Help. The right side has widgets that give users quick information about the NAS such as its name and OS version, networking connections, storage capacity used and resource utilization.

The Control Panel lets users see and change Privileges, Network Services, Storage, General Settings, and System information. Drilling down through Storage Manager users can further go into Hard Drive, RAID, iSCSI Target, Virtual Disk, and External Storage. Here they can create, edit, or delete items such as storage pools and RAID configurations.

System Information gives users a quick run down of everything in the NAS from what hardware is installed, to service statuses, resource monitor, and systems logs.

The Applications App is a basic App store for users to install or uninstall applications compatible with the NAS. Though overall it does seem to be lacking compared to other NAS OS's on the market.


Enterprise Synthetic Workload Analysis

Our enterprise shared storage and hard drive benchmark process preconditions each drive into steady-state with the same workload the device will be tested with under a heavy load of 16 threads with an outstanding queue of 16 per thread, and then tested in set intervals in multiple thread/queue depth profiles to show performance under light and heavy usage. Since hard drives reach their rated performance level very quickly, we only graph out the main sections of each test.

Preconditioning and Primary Steady-State Tests:

  • Throughput (Read+Write IOPS Aggregate)
  • Average Latency (Read+Write Latency Averaged Together)
  • Max Latency (Peak Read or Write Latency)
  • Latency Standard Deviation (Read+Write Standard Deviation Averaged Together)

Our Enterprise Synthetic Workload Analysis includes four profiles based on real-world tasks. These profiles have been developed to make it easier to compare to our past benchmarks as well as widely-published values such as max 4k read and write speed and 8k 70/30, which is commonly used for enterprise drives.

  • 4K
    • 100% Read or 100% Write
    • 100% 4K
  • 8K 70/30
    • 70% Read, 30% Write
    • 100% 8K
  • 8K (Sequential)
    • 100% Read or 100% Write
    • 100% 8K
  • 128K (Sequential)
    • 100% Read or 100% Write
    • 100% 128K

For our testing we configured the TerraMaster F2-221 in RAID1 in both iSCSI and CIFS using Toshiba N300 NAS 8TB hard disk drives.

In the first of our enterprise workloads, we measured a long sample of random 4K performance with 100% write and 100% read activity. Looking at IOPS the F2-221 had performance of 195 IOPS write and 726 IOPS read using iSCSI connectivity, while CIFS showed an improved 262 IOPS write and 788 IOPS read.

Looking at 4K average latency, the TerraMaster NAS hit 351.94ms read and 1,310.47ms read in iSCSI and 986.72ms write and 324.80ms read in CIFS.


Switching over to 4K max latency the F2-221 had 18,727ms read and 32,775ms write in CIFS while iSCSI saw a much better 1,065.7ms read and 30,748ms write. 

For 4K standard deviation we saw 2,937.37ms write and 568.32ms read in CIFS and 2,984.11ms write and 189.97ms read in iSCSI. 

Our next benchmark measures 100% 8K sequential throughput with a 16T16Q load in 100% read and 100% write operations. Here, the TerraMaster NAS showed much better write performance with 21,078 IOPS vs. 13,247 IOPS in iSCSI; though iSCSI showed much better read performance with 22,197 IOPS vs 14,490 IOPS CIFS.

Compared to the fixed 16 thread, 16 queue max workload we performed in the 100% 4K write test, our mixed workload profiles scale the performance across a wide range of thread/queue combinations. In these tests, we span workload intensity from 2 threads and 2 queue up to 16 threads and 16 queue. In throughput, the F2-221 showed a range of 322 IOPS to 581 IOPS. For CIFS, we had a much better range of 565 IOPS to 750 IOPS.

In average latency, though it started slow in the early queue depths, the F2-221 showed its best performance in CIFS with a range of 56.63ms through 170.3ms IOPS. iSCSI recorded a range of 12ms to 439.44ms.

For maximum latency, results were very similar by the end of the test, which posted 14,978.9ms and 14,719ms CIFS and iSCSI respecitively (16 Threads 16 Queue).

Looking at standard deviation, the F2-221 CIFS configuration recorded 390.96ms to 701.42ms, while the iSCSI configuration showed a range of 52.95ms to 1248.98ms.

The last Enterprise Synthetic Workload benchmark is our 128K test, which is a large-block sequential test that shows the highest sequential transfer speed for a device. In this workload scenario, the F2-221 had 203.2MB/s write and 193.5MB/s read in CIFS and 186.0MB/s write and 207.5MB/s read in iSCSI. 


The TerraMaster  F2-221 is compact NAS that is equipped with a capable Intel dual-core processor and up to 8GB of RAM. This 2-bay NAS is aimed at SOHO use cases and home users looking for a personal cloud or a storage solution with some multimedia capabilities, such as real-time 4K video transcoding. The F-221 features components that can certainly handle these applications.

For performance, we looked at straight RAID1 HDD performance in both CIFS and iSCSI connectivity, leveraging two Toshiba N300 NAS 8TB drives. Looking at IOPS during our 4K tests, the F2-221 posted195 IOPS write and 726 IOPS read in iSCSI, and an improved 262 IOPS write and 788 IOPS read in CIFS. In our 100% 8K sequential throughput, the  F2-221  showed much better write performance in CIFS with 21,078 IOPS vs. 12,247 IOPS in iSCSI; however, iSCSI recorded much better read performance with 22,197 IOPS vs 14,490 IOPS in CIFS. During our large-block sequential test, the F2-221 had 203.2MB/s write and 193.5MB/s read in CIFS and 186.0MB/s write and 207.5MB/s read in iSCSI. 

The TerraMaster F2-221 is a small NAS that can bring solid performance to home and small business environments. The NAS is cost-effective and can handle most of the tasks smaller offices need it to handle.

TerraMaster F2-221 on Amazon

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