Throughput and adaptability of USB 3.0 hub versus 4 port PCI-E 4x


#1

Hello, Plugable,

I have just ordered your Plugable USB 3.0/2.0 SATA Hard Drive Docking Station (LucidPort chipset) from Amazon, and plan to order several more. These will be used with a variety of Operating Systems (Solaris, Mac OS X, Windows, Linux) and I’m trying to figure out which hardware will give the best speed. How would four of these connected to your Plugable 4-Port SuperSpeed USB 3.0/2.0 Hub to a single USB 3.0 compare to directly connecting these four to a Highpoint 4 port USB 3.0 RocketU 1144:

http://www.highpoint-tech.com/USA_new…

I’m aware that it would be rare to get maximum theoretical throughput, but I wonder if the 4 amps on the hub would compensate for having fewer “lanes” on the PCI-E connection.

I would try to connect it to your 2 port USB 3.0 ExpressCard adaptor, but I’m not familiar with the Renesas chipset, and I don’t know if it would play well with Solaris and Linux. I would also need to buy a 34mm (is that right?) Express Card to PCIe slot, and that would add a further complication to running this on multiple OS’s.

I’m not too worried either way, because I’m assuming the USB 3.0 steps down to 2.0 automatically, and I can wait and see if kernel extensions or firmware updates increase the speed.

Thank You,

Gordon Bynum


#2

Hi Gordon,

Thanks for asking ahead! Current USB 3.0 hubs (e.g. using the most popular VL810 chipset) aren’t as mature yet as the USB 2.0 generation. There are often compatibility and performance tradeoffs. We’re hoping upcoming USB 3.0 hub controllers will make progress and eliminate these issues.

So for now, we don’t recommend combining our USB 3.0 SATA dock with a USB 3.0 hub, if you can avoid it.

In terms of which USB host controller to buy, the Renesas chipset is by far the most common and well supported. Renesas is NEC’s chipset division (spin-off).

The Renesas works well with Windows (using Renesas’ driver in Win7 and prior; with Microsoft’s own drivers in Win8) and it works well with Linux – support in 3.X is solid, and we’ve been donating hardware to several of the Linux kernel developers, so we know our Renesas-based PCIe board (http://plugable.com/products/pcie-usb…) works well.

That highpoint-tech USB host controller looks like it uses a PLX chipset, which we wouldn’t recommend. PLX appears to be exiting the consumer business (http://www.plxtech.com/about/news/pr/…).

If you want a 4-port host controller, probably one based on a VIA or TI chipset is a better choice.

Hope that helps. Let us know if you have any trouble at all
Bernie


#3

Hello, Bernie,

Many thanks for your help. The USB 3.0 Docking Station arrived today, but, sadly, after less than an hour of use, the hard drive was more than a little warm to the touch, and it stopped working. Drive Genius gave a “hardware error” when I tried to scan the disks, and I get the same results with either cable.

The Model Number is: USB3-SATA-U3
Serial No.: 5768001300225

I’ve also tried two different 2.5 inch sata drives, same result, using a MacBook Pro.

That’s too bad, because I needed it this weekend. The AC Adapter appears to be working, at least it did initially:

Model NO: WT1202000
Input: 100-240Vac 50/60Hz 1.6A
Output: 12V ———2.0A

So I’m not sure what more I can do for troubleshooting, so I’m guessing I’ll return it to Amazon as defective.

I would love to get your PCIe to USB 3 expansion card, but it only has two slots, and I would want to connect 4 to 8 USB drives in an array (this would be a zpool for Solaris ZFS). So there would not be enough PCIe slots on the board (2, at present). So do you, or someone else, make a Renesas chipset PCIe to USB 3 card with 4 USB 3 slots? That would help.

I appreciate the heads up about USB 3.0 hubs. I was thinking of using them like a cheaper version of a Myrinet cluster drive tree, but I suppose it’s a matter of time before the USB 3 hubs can do that consistently.

Well, I’m sorry about that, but it looks like I got a lemon. I very much like your support, and your products, but I’ll have to get something else on this short notice, probably WiebeTech, Oyen Digital, or ineo.

Many Thanks.


#4