QNAP Goes Bay Trail

Intel's Bay Trail-D takes the original Bay Trail configuration pretty much as-is. One of Intel's marketing slides for Bay Trail-D (and -M) is reproduced below for aiding our analysis.

Despite not being specifically mentioned, we know there are two SATA II (3 Gbps) ports in Bay Trail-D from the previous section. Combined with the four PCIe 2.0 lanes, the configuration is pretty much similar to the Atom D2700 along with a NM10 chipset in terms of I/O. The advantage is that all the high-speed I/Os come direct from the SoC and are not bottlenecked by DMI lanes, and the PCIe revision is 2.0 instead of 1.0. In addition, we also have a USB 3.0 port.

The Celeron J1800 used in the TS-x51 is a 2C/2T solution with a base frequency of 2.41 GHz and a burst speed of 2.58 GHz. With a 10W TDP, it is amenable to passive cooling with the appropriate chassis, but, in a NAS like the x51, it is a moot point since the drives require cooling anyway. The TS-x51 series comes in 2,4,6 and 8-bay varieties and all of them come with two GbE ports. While the 2 and 4-bay varieties come with 2x USB 3.0 ports, the 6 and 8-bay ones come with 3x USB 3.0 ports. Based on the above information, we can infer the following distribution of the high-speed interfaces amongst the various I/Os.

QNAP TS-x51 Series High-Speed I/O Usage [ UPDATED ]
SoC I/O TS-251 TS-451 TS-651 TS-851
PCIe 2.0 x1 GbE Port 1 GbE Port 1 GbE Port 1 GbE Port 1
PCIe 2.0 x1 GbE Port 2 GbE Port 2 GbE Port 2 GbE Port 2
USB 3.0 x1 2x USB 3.0 (Hub) 2x USB 3.0 (Hub) 3x USB 3.0 (Hub) 3x USB 3.0 (Hub)
PCIe 2.0 x2 Free for Drive Bays

While the 2-bay unit is capable of having probably all I/Os accessible through the SoC fabric at full speeds, the 4-,6- and 8-bay varieties need some trade-offs. [Update: QNAP confirmed that they are using a USB 3.0 hub chip as one of the commenters pointed out]. In the above table, we see that two PCIe 2.0 lanes and two SATA II (3 Gbps) lanes are available for connecting all the drives in the bays to the SoC. In the absence of a I/O Controller Hub (that made the previous generations of Atom-based NAS units simple to design), each vendor is now free to choose between a number of different available options.

An issue with the Celeron J1800 (and Bay Trail-D in general) is that the SATA ports don't support port multipliers. In addition, there is only one SATA controller behind the two SATA ports. This places undue stress on the two free PCIe link to service a large number of bays. Our educated guess is that QNAP uses a number of PCIe to SATA bridges (such as  the Marvell 88SE9130 and the ASMedia ASM1061 for PCIe x1 to 2x SATA and Marvell 88SE9215 for PCIe x1 to 4x SATA). This still doesn't explain how the TS-851 is configured (I am yet to see a PCIe x1 to 6x SATA bridge chip). It will be interesting to see the break-up, but, at this moment, QNAP has not got back with answers to our clarification requests. The addition of two USB 3.0 ports to the 6- and 8-bay models actually takes away a PCIe x1 lane that could have otherwise been used for the drive bays. I am not sure how many users need more than one USB 3.0 slot in a NAS.

Update: QNAP came forward with clarifications on the I/O distribution:

  • TS-251: 1x ASM1061 (i.e, two SATA ports are served by one PCIe link)
  • TS-451: 2x ASM1061 (four SATA ports from two PCIe links)
  • TS-651: 2x 88SE9215 (three SATA ports per PCIe link)
  • TS-851: 2x 88SE9215 (four SATA ports per PCIe link)

Coming back to the Celeron J1800 SoC, the two features most relevant to us in this piece are the availability of Quick Sync (something not claimed in the initial Bay Trail launch) and VT-x (support for virtualization). We will be covering this in the next two sections. Prior to that, a quick note on the J1800 which has both 2013 B3 as well as 2014 C0 steppings. Intel started playing up the Quick Sync capabilities of the Bay Trail-D / Bay Trail-M parts for products which are part of the push for the 'Back-to-School 2014' season.

It appears from the above slide that only the 2014 C0 steppings of the J1800 have QuickSync enabled (we are still waiting for confirmation from Intel on this). Since the hardware accelerated transcoding features of the TS-x51 are dependent on Quick Sync, it is obvious that the TS-x51 must be using the C0 stepping of the Celeron J1800.

Intel Storage Platforms for the NAS Market Hardware Accelerated Transcoding for Media Applications
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  • ganeshts - Monday, June 23, 2014 - link

    In a comment on another recent article, one of the readers stressed that deinterlacing is broken in the Linux drivers for the iGPU. I will check on the status with a review sample
  • DanNeely - Sunday, June 22, 2014 - link

    Two questions, the first is a repeat from the initial announcement a week ago. What virtualization platform/virtual drive container format(s) is supported?

    The second is, why assume the additional USB3 is done by consuming a PCIe lane instead of by sticking a USB3 hub onboard as is common with current generation motherboards.
  • modulusshift - Sunday, June 22, 2014 - link

    It would consume a PCIe lane either way. He's talking about total lanes from the CPU, not just the number a motherboard would expose like on normal desktops.
  • ganeshts - Monday, June 23, 2014 - link

    I am not sure I understand the question entirely, Dan.

    Are you saying that current generation mobos have the ability to make a single USB 3.0 port from the PCH appear as multiple USB 3.0 ports on the board, i.e, is there a 'USB 3.0 port multiplier' that you are talking about?

    As modulusshift indicates, most of the NEC / Fresco Logic / ASMedia based USB 3.0 ports that I see in the motherboards all communicate with the PCH using a PCIe lane.
  • DanNeely - Monday, June 23, 2014 - link

    Yes. A lot of the current generation of boards offering 8 or more USB3 ports that have been reviewed on this site recently are being called out for using a cheaper USB3 hub chip (like what would be inside a 2/4 port USB3 hub on your desk) instead of a PCIe-USB3 chip like in the previous generation.

    4 of 5 mobo reviews on the front and second page call the board out for using at least on hub to add USB3 ports, just search the first page of the review for the word hub (the 5th only had 6 ports and presumably didn't need one):
  • ganeshts - Monday, June 23, 2014 - link

    Got it! Let me see what QNAP comes back with, and I will update the article accordingly.
  • DanNeely - Monday, June 23, 2014 - link

    Not a problem. This is something fairly new; and unfortunately appears to be occurring at all pricepoints. I'm mostly ok with doing it on budget boards; but for higher end ones I'd much rather have the option of a 2:4 or 4:8PCIe lane PLX and PCIe-USB3 controllers powering all the ports, rather than have to worry about where I connect high bandwidth devices in the future to avoid bottle-necking. I'm really hoping skylake's chipset will have enough native usb3 ports to make this generation's designs a one off aberration.
  • ganeshts - Wednesday, June 25, 2014 - link


    Virtualization answers from QNAP: OVA, OVF, QVM, XML, VMX.

    Confirmed that an USB 3.0 hub chip is being used

    SATA - PCIe bridge list update in the article.
  • extide - Monday, June 23, 2014 - link

    No, if you used a USB 3.0 HUB then it would not use a PCIe lane, and that would leave you with two PCIe x1 lanes, so you could add two controllers (ex for the 8-bay you would need a 4-port and a 2-port).
  • name99 - Sunday, June 22, 2014 - link

    I find the premise of the article ("Intel Quick Sync Gets its Killer App") to be quite bizarre.
    In the Apple world, QuickSync has had its killer app for some time supporting remote desktops and video sent from a Mac to an AppleTV. For remote desktops in particular, while this was previously done with software encoding, the lowered latency of QuickSync makes a noticeable difference to the usability if you're connected via a high bandwidth connection. I expect there are substantially more people using OSX ARD than will ever buy this particular NAS.
    There are probably similar use cases happening on Windows, but I don't know much about that side of the fence.

    My point is not to criticize the NAS or talk up OSX; it's simply to point out that the article subtitle is more than a little ridiculous, suggesting, as it does, that poor little QuickSync was just out there languishing in the world with everyone ignoring it until this NAS came along and showed the world how to utilize it.

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