Performance with SSDs

Storage bridges operate in the maximum possible performance mode when the storage media is able to saturate the SATA links. SSDs are best suited for this purpose. Our first set of tests help in understanding how the TerraMaster D2-310 behaves with Crucial MX200 500GB SSDs in the drive bays.

CrystalDiskMark uses four different access traces for reads and writes over a configurable region size. Two of the traces are sequential accesses, while two are 4K rando accesses. Internally, CrystalDiskMark uses the Microsoft DiskSpd storage testing tool. The 'Seq Q32T1' sequential traces use 128K block size with a queue depth of 32 from a single thread, while the '4K Q32T1' ones do random 4K accesses with the same queue and thread configurations. The plain 'Seq' traces use a 1MiB block size. The plain '4K' ones are similar to the '4K Q32T1' except that only a single queue and single thread are used.

Comparing the '4K Q32T1' and '4K' numbers can quickly tell us whether the storage device supports NCQ (native command queuing) / UASP (USB-attached SCSI protocol). If the numbers for the two access traces are in the same ballpark, NCQ / UASP is not supported. This assumes that the host port / drivers on the PC support UASP. We can see that the TerraMaster D2-310 supports UASP. The bridge is also able to sustain as much as 685 MBps for certain workloads.

Storage Bridge Benchmarks - CrystalDiskMark

Moving on to the real-world benchmarks, we first look at the results from our custom robocopy test. In this test, we transfer three folders with the following characteristics.

  • Photos: 15.6 GB collection of 4320 photos (RAW as well as JPEGs) in 61 sub-folders
  • Videos: 16.1 GB collection of 244 videos (MP4 as well as MOVs) in 6 sub-folders
  • BR: 10.7 GB Blu-ray folder structure of the IDT Benchmark Blu-ray (the same that we use in our robocopy tests for NAS systems)

The test starts off with the Photos folder in a RAM drive in the testbed. robocopy is used with default arguments to mirror it onto the storage drive under test. The content on the RAM drive is then deleted. robocopy is again used to transfer the content, but, from the storage drive under test to the RAM drive. The first segment gives the write speed, while the second one gives the read speed for the storage device. The segments end with the purge of the contents from the storage device. This process is repeated thrice and the average of all the runs is recorded as the performance number. The same procedure is adopted for the Videos and the BR folders. Readers interested in looking at all the graphs in one shot can choose the 'Expand All' option in the dropdown menu.

Photos Read

High-performance external storage devices can also be used for editing multimedia files directly off the unit. They can also be used as OS-to-go boot drives. Evaluation of this aspect is done using PCMark 8's storage bench. The storage workload involves games as well as multimedia editing applications. The command line version allows us to cherry-pick storage traces to run on a target drive. We chose the following traces.

  • Adobe Photoshop (Light)
  • Adobe Photoshop (Heavy)
  • Adobe After Effects
  • Adobe Illustrator

Usually, PC Mark 8 reports time to complete the trace, but the detailed log report has the read and write bandwidth figures which we present in our performance tables. Note that the bandwidth number reported in the results don't involve idle time compression. Results might appear low, but that is part of the workload characteristic. Note that the same CPU is being used for all configurations. Therefore, comparing the numbers for each trace should be possible across different DAS units. Readers interested in looking at all the graphs in one shot can choose the 'Expand All' option in the dropdown menu.

Adobe Photoshop Light Read

Thermal Aspects and Power Consumption

The thermal design of external storage enclosures has now come into focus, as high-speed SSDs and interfaces such as USB 3.1 Gen 2 can easily drive up temperatures. This aspect is an important one, as the last thing that users want to see when copying over, say, 100 GB of data to the drive inside the enclosure, is the transfer rate going to USB 2.0 speeds. In order to identify the effectiveness with which the enclosure can take away heat from the internal drive, we instrumented our robocopy DAS benchmark suite to record various parameters while the robocopy process took place in the background. Internal temperatures can only be gathered for enclosures that support S.M.A.R.T passthrough. Readers can click on the graphs below to view the full-sized version. Thanks to the active cooling in the chassis, there are no thermal or performance consistency issues.

Storage Enclosure Thermal Characteristics

The power consumption at the wall was tracked while the CrystalDiskMark workloads were processed. The workloads were set up with an interval time of 30s. The numbers are graphed below for both RAID cases. The peak was around 10.5 W, while the unit with two SSDs idled around 4.3 W.

Power Consumption - CrystalDiskMark Workloads
Introduction Performance with Hard Drives
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  • SilthDraeth - Wednesday, July 5, 2017 - link

    So, they copy the Cooler Master logo... close enough anyway, and as far as I know, they are not affiliated or part of Cooler Master... Isn't this something that the company could be sued for...

    Or did Cooler Master steal the design?
  • menthol1979 - Thursday, July 6, 2017 - link

    $159 for this piece of crap? With a few bucks more you can get an outstanding Synology DS216j, way better than this garbage can in a thousand ways.
  • ganeshts - Thursday, July 6, 2017 - link

    You are comparing apples and oranges. Show me the case where the DS216j can sustain 600 MBps to your PC. This is a DAS, while the 216j is a NAS.
  • jabber - Thursday, July 6, 2017 - link

    Indeed, sometimes you just want a place where you can dump and use a large amount of data fast. A Synology or any NAS isn't going to do that.
  • menthol1979 - Thursday, July 6, 2017 - link

    True, considering the 600 MBps as SSD RAID0 sequential file transfer only, which is hardly a common use scenario. For most other uses, as you have marvelously illustrated indeed, its performance hardly exceeds the 100MB/s DS214j's speed. This is why I believe that these two products can, in many was, compare. And an entry-level NAS can win.
  • UpSpin - Thursday, July 6, 2017 - link

    Only if you transfer one large file. It's quite different if you copy many small files (which is the usual scenario). Your NAS won't be able to keep the high transfer rate and drop to a fraction of the possible gigabit LAN speed. It's getting worse if you use an encryption. On the other hand, the DAS is only restricted by the CPU of the much more powerful PC.
  • jabber - Thursday, July 6, 2017 - link

    Yeah I never use my NAS boxes for big data transers of varied small files. Life is too short. As direct to storage as possible.
  • jmke - Friday, July 7, 2017 - link


    if you're going to spend money a scratch disk; there are cheaper alternatives with a lot more disks;
  • dave_the_nerd - Monday, July 17, 2017 - link

    So, you don't know the difference between DAS and NAS, and why they are both better solutions for different types of needs?
  • Lolimaster - Monday, July 10, 2017 - link

    I just want a box like this without any additional raid sh*t, just a simple HDD/SSD aluminium enclosure + USB 3.0-3.1g2 adapter and the power brick/optional to run on usb 3.1 alone.

    Nothing extra, just that.

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