PLX bridges gap between USB 3.0 and PCIe 2.0

Add PLX to the growing list of companies developing USB 3.0 hardware. The company is bringing its expertise in bridge chips to the SuperSpeed spec with a pair of peripheral controllers that link PCI Express with USB 3.0. SemiAccurate has the skinny on the two chips, which can be used to hang PCIe devices off USB ports or vice versa.

The USB 3380 offers a single USB 3.0 port and one lane of gen-two PCI Express connectivity. You still only get a lone USB port with the 3382, but there’s a pair of PCIe lanes with a couple of configuration options. The lanes can be used to attach a pair of PCIe devices, or they can combine to provide a faster pipe to a single peripheral. A single PCIe 2.0 lane offers about 500MB/s of bandwidth in each direction, while one USB 3.0 port can push closer to 600MB/s, at least in theory.

SemiAccurate notes that the PLX chips are capable of faking device types to fool the host system, a feature that should make it easier to connect PCIe devices via USB. External graphics cards are named as one possible implementation, although I can’t help but wonder if little more than a single PCIe lane’s worth of bandwidth would be sufficient for modern games. Of course, the USB-IF has yet to certify the PLX chips, which will only be shipping in sample form in the first half of this year. Mass production isn’t expected to begin until the third quarter.

Comments closed
    • shank15217
    • 9 years ago

    This is gonna rain on Intel’s thunderbolt, let the battle begin 🙂

    • krazyredboy
    • 9 years ago

    This makes me happy, as it could allow for the development of USB 3.0 adapters to Firewire. At least, in the case of my laptop, where I have USB 3.0 but no ability to add Firewire, as it is.

    • not@home
    • 9 years ago

    For some reason I have not been able to look at anything on [url<]http://semiaccurate.com[/url<] in a very long time. I do not get it.

    • Farting Bob
    • 9 years ago

    Only 1 USB port per chip (for the cheaper option)? People are used to having everything plugged into USB ports, if they have to pick and choose who gets the fast ones they wont be happy.

    • dpaus
    • 9 years ago

    [i<]"I can't help but wonder if little more than a single PCIe lane's worth of bandwidth would be sufficient for modern games"[/i<] -- geez, guys, not [i<]everything[/i<] has to do with games. I'd be happy to be able to drive an additional monitor from a USB 3.0 port on my laptop for 'business apps' uses, just to get around the &%$^& "two-displays-is-all-you'll-ever-need" limitation of it's built-in GeForce 435M graphics.

      • demani
      • 9 years ago

      [url<]http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/25.html[/url<] Well, running a 5870 at 75% performance actually wouldn't be terrible, so that says something. Like WoW with decent settings on a laptop with integrated graphics would be possible.

        • dpaus
        • 9 years ago

        Wow – I had no idea that x8 and even x4 was that close to x16. This could cause me stop sneering at motherboards that provide four x16 physical slots that only run at x8 or even at x4 when fully stuffed.

        EDIT: ps – thanks for the link; I’m going to share that with my fellow techies at work this morning.

    • HisDivineShadow
    • 9 years ago

    The USB-IF still hasn’t certified any non-NEC USB3 controllers, have they? Are/Were they paid by NEC to stonewall the adoption of other controllers or perhaps paid by Intel to stonewall the adoption of USB3 by keeping the controller expensive with lack of competition?

      • iq100
      • 9 years ago

      Some Fresco chips have received USB3 certification:
      [url<]https://techreport.com/discussions.x/20304[/url<] iq100 the best way to delete an idea is to post one of your own.

    • zdw
    • 9 years ago

    I wouldn’t be surprised to see external graphics cards using this. Will be interesting to see how it competes with the Intel/Apple Thunderbolt technology – this is considerably slower, but if it’s cheaper and “fast enough” it might make serious inroads.

      • HisDivineShadow
      • 9 years ago

      Somehow, I doubt the user who needs external PCIe is going to want to save a few dollars on this. That’d be the performance user and it’d already be pretty niche…

      • OneArmedScissor
      • 9 years ago

      Just like expresscard! Oh…wait…

      Since every CPU from here on out has an on-die PCIe 2.0 controller, there’s no reason to bother with these bizarre spider webs of back and forth between tons of controllers with increased latency and limited bandwidth.

      Expansion devices for laptops shouldn’t really have to work any differently than they do for desktops. I don’t understand what’s going on here at all, but this is laptops we’re talking about here. Just spray gloss all over the place and everything will be ok.

Pin It on Pinterest

Share This