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External Graphics Over PCIe 3.0? Netstor's NA255A, Reviewed

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Netstor sent over its TurboBox NA255A, an external enclosure capable of accommodating four dual-slot graphics cards across one 16-lane PCI Express 3.0 connection. Is this thing fast enough for general-purpose GPU compute workloads? How about gaming?

Power And Heat

The following chart is a little difficult to follow, so I'll break it down like this: the blue bar represents our PC on its own, the red bar is the TurboBox on its own, and the black bar is our PC plus the TurboBox attached.

Naturally, in half of the configurations, there's a missing red bar. This is because the TurboBox isn't being used when we plug our graphics cards into ASRock's X79-based motherboard. In the other half of the charts, the PC bar is incredibly short. That is the result of applying a heavy bitcoin mining load to graphics cards in the TurboBox, which doesn't affect the PC all that much.

As you can see, the TurboBox/PC combo uses about 100 to 150 W more than the PC alone. There's some overhead to accommodate the extra hardware, which we'd expect.

Although using the TurboBox increases power consumption, the cards themselves run cooler as a result of the NA255A's optimized airflow. Moreover, the PC's other components don't end up being subjected to additional heat from a multi-GPU configuration on the motherboard.

67 Comments Comment from the forums
  • ohyouknow
    Interesting
    Reply
  • MasterMace
    This is a nice article. I wonder if Tom's can do a multi-cpu article as well.
    Reply
  • dagamer34
    Now if only we could get external GPUs via Thunderbolt (or it's future iterations) so that laptops wouldn't be forever gimped, we'd be in business!
    Reply
  • Whooo whoo, if i had the money to burn, i would get this NA255A, remove the PSU bundle, replace it with a Seasonic 1000 Platinum, slap four GTX Titans, add a custom water-cooling loop, connect it to my main PC and have (if it works) three more NA255A's for each of the PCIe for the main PC with a grand total of 16 GTX Titans for massive GPU computation. All for a grand total of $13,800. Massive electric bill, here i come!
    Reply
  • mayankleoboy1
    PCIE signals scale poorly to long wires. So it is a technical achievement to have these signals travel over a meter of wire.
    Reply
  • A Bad Day
    dagamer34Now if only we could get external GPUs via Thunderbolt (or it's future iterations) so that laptops wouldn't be forever gimped, we'd be in business!
    There are some external GPU cases.

    The only issue is that the cheapest is somewhere slightly less than $400.

    Please explain to me how an aluminum box, a micro-PSU, and a Thunderbolt-to-PCIE adapter adds up to even $200...
    Reply
  • A Bad Day
    EDIT: And when I meant the cheapest, I meant the ones that are only sufficient for a 7750. Want to pair a 7970 with a ultrabook?

    $400-$500 for a slightly longer box with a slightly more capable PSU.
    Reply
  • slomo4sho
    An expensive solution to inferior Mac hardware...
    Reply
  • Vatharian
    Good X79 workstation mobo with 7 PCI-e slots, and 4 K20x-s on each of them. That's a TON of computing power, and if you don't want to deal with high-speed networking multiple boxes, that's nice. Of course only if this thing can actuallty work in pairs or more and in some way circumvent the 15 gpu limit in bios memory mapping. Can this thing be turned on with working machine?
    Reply
  • adgjlsfhk
    But what about someone working on a Mac Pro? Apple's more limited ecosystem means there is no such thing as a three- or four-way graphics array. This could be one of the only options for enabling multiple GPUs. If massive compute potential is important, you might need to swallow hard and consider Netstor's solution the cost of doing business in Apple's world.
    Or you could use the $2000 to ditch your mac pro that is years out of date and use the money to buy a pc that is better in pretty much every way.
    Reply