Thecus N4800: Testbed in Action

We have been evaluating the Thecus N4800, a 4-bay NAS unit based on the Atom D2700, over the last few months. A full length detailed reviewhas been put on the backburner because of some firmware issues related to RAID migration and rebuild. However, many other reviews have observed that it is one of the top performers with respect to raw data access speeds. We had put the unit through the new test suite with four disks in RAID5 in our previous piece, and the N4800 had emerged with its head held high even with 12 simultaneous clients.

We repeated our test after increasing the number of clients to 25. The following four graphs show the total available bandwidth and the average response time while being subject to different types of workloads through IOMeter. IOMeter also reports various other metrics of interest such as maximum response time, read and write IOPS, separate read and write bandwidth figures etc. Selected metrics from the evaluation of the Thecus N4800 are available here.

The updated testbed finally gives pointers towards the potential weaknesses of the Thecus N4800. Under environments with more than 15 clients doing simultaneous sequential reads and writes, performance starts to degrade. On the other hand, pure sequential reads manage to saturate the link-aggregated GbE ports even up to 25 clients.

One of the important aspects not reflected in the above graph is the maximum response time. The values are available in the detailed results summary. Some transactions (even sequential reads) can take around 30 seconds to complete, and this might not be acceptable for some usage scenarios.

Updating the Testbed - External Infrastructure Concluding Remarks
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  • Andrew911tt - Thursday, November 29, 2012 - link

    From what I understand the OCZ RevoDrive Hybrid is being used just as a PCI-e to Sata converter is that correct?

    I understand the changes that you made on the external network setup, but my question is why did you make this change?
    Reply
  • ganeshts - Thursday, November 29, 2012 - link

    1. Yes, and we also got 100 GB of NAND as a new drive for the host OS to access

    2. Our previous external network setup (ZyXel switch) had only 24 ports. With 12 VMs, we had plenty of spare ports for the management port and for the NAS units. When moving to 25 VMs, we ran out of ports in the switch. The second reason is that we are planning to evaluate 10 GbE NAS units in the future and it is important to have a switch capable of 10 GbE for that purpose.
    Reply
  • Andrew911tt - Thursday, November 29, 2012 - link

    I understand what you did, but why did you create the separate sub-nets and isolate them from the internet like in first set up. Reply
  • ganeshts - Friday, November 30, 2012 - link

    We wanted to eliminate unnecessary / unintended traffic from the machines on the live network (192.168.1.x) to the NAS or even the VMs themselves. Reply
  • SunLord - Friday, November 30, 2012 - link

    Why are you using a stupid Revo. You should of gotten an SAS HBA and used 5.25" to 4 x 2.5" bay adapters then you could of put in upto 20 2.5" ssd and an optical drive. Reply
  • SunLord - Friday, November 30, 2012 - link

    Something like this is what i meant for the 4x2.5" adapter

    http://www.newegg.com/Product/Product.aspx?Item=N8...
    Reply
  • Flunk - Friday, November 30, 2012 - link

    Or simply add hang extra bays from the roof of the case. Reply
  • Plifzig - Friday, November 30, 2012 - link

    So, were all the SATA ports occupied? Or were they just all taken? Sounds like they were occupied.

    And also taken.
    Reply
  • KranZ - Friday, November 30, 2012 - link

    Were you using the default 1500 byte MTU or did you bump the interfaces and VMs up to 9000 byte MTUs? Reply
  • kenyee - Friday, November 30, 2012 - link

    Could you guys please test these things for noise/heat w/ more drives when you test cases?
    E.g., the Nanoxia Deep Silence review recently. Looks like it'd be perfect for something like your SOHO NAS. It was tested w/ an SSD and no hard drives :-P
    The case in this review had a hard drive card.
    If you have so many slots, why would you not load it up?
    And if you're using a camera like the D800 w/ 50MB RAW files and trying to do video w/ terabytes of raw footage, you're going to load it up w/ hard drives...
    Reply

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