All posts by Jerome Myers

My background is in electronics with experience in semiconductor capital equipment installation and support. I've become more interested in software in recent years and have been growing my skill sets in Linux system administration, web programming and infosec. I've particularly enjoyed Plugable Technologies because as employees we are empowered to do the right thing for our customers, every time.
Plugable's Testing Station for Charging Behavior

The State of USB Charging

The humble Universal Serial Bus, more commonly known as USB has evolved to be much more than just a way to connect a mouse or keyboard to your computer. With the proliferation of power hungry portable devices that charge over USB, we’ve all come to expect USB to operate as a Universal Source of Battery charging, but unfortunately it’s just not that easy.

The original USB 2.0 specification limited the power that could be drawn from any USB port to 500mA. This is plenty to charge smaller batteries reasonably quickly, but for larger batteries a higher power solution is needed. This has driven device makers to come up with novel ways to draw more than the allowed 500mA from USB 2.0 ports and in general has been accomplished by the USB port signaling to the devices that it’s ok for the device to draw current at a higher rate.

Unfortunately there hasn’t been a widely adopted standard, so not all ports and devices speak the same language when it comes to charging. And, to make the situation even more frustrating for end users, there hasn’t been much public discussion or documentation about what has been done.

iPads for example, are one device that can charge at a very quick rate, up to 2.1Amps when connected to an Apple computer or Apple charger but they will potentially not charge at all when connected to a regular USB port. There’s also the BC 1.1 charging standard that some devices like the Kindle Fire or the Nexus 7 support, but that support is usually undocumented. We find out about charging behavior through trial and error.

So, try we did! We’ve been working hard to unravel the mysteries of what will charge where by testing every device we have on all of our hubs and chargers, and publishing this data on the product pages for each of our devices with USB ports.

We’re also collecting reports from end users though a quick form that let’s you add to the knowledge base of charging behavior.

Here’s what’s been added so far:

To add your device visit:

Check the FAQ on each of these pages for the details of our in-house test results.

The new Plugable USB 3.0 SATA Lay-flat Dock with support for UASP, 4TB+ drives, and market leading USB 3.0 performance

Plugable’s new USB 3.0 lay-flat external SATA hard drive docking station focuses on cutting-edge performance, compatibility, and design.

Featuring easy USB host and SATA drive compatibility, it comes with the latest ASMedia 1053 chipset, featuring capabilities including:

  1. Automatic, driverless compatibility with all computing devices which already support USB flash drives or USB hard drives. Full backward compatibility with USB 2.0.
  2. Supports UASP (USB Attached SCSI Protocol) Specification Revision 1.0 for maximum performance on supported operating systems like Windows 8. The OS, host controller, and device must all support UASP to switch over to this higher performance transfer mode.
  3. “The adoption of the SCSI Protocol in USB 3.0 provides its users with the advantage of having better data throughput than traditional BOT (Bulk-Only Transfer) protocol, all thanks to its streaming architecture as well as the improved queuing (NCQ support) and task management, which eliminated much of the round trip time between USB commands, so more commands can be sent simultaneously. Moreover, thanks to the multi-tasking aware architecture, the performance is further enhanced when multiple transfers occur.”

  4. Supports USB Super-Speed, High-Speed and Full-Speed Operation, so the dock is backward compatible with any USB-capable computing device with USB Mass Storage support, for example the Raspberry Pi hobby board or Microsoft Surface or Toshiba Thrive Android tablet.
  5. Supports USB Mass Storage Class, Bulk-Only Transport Specification Revision 1.3
  6. Serial ATA bus up to 3/6Gbps Signal bandwidth for fast storage backups
  7. Support Spread Spectrum Control of USB3.0 and SATA interface to improve EMI performance, lowering USB 3.0 interference with other wireless devices such as mouse, keyboard, or Bluetooth
  8. Compatibility

    Works with all SATA drives, including 2.5″ and 3.5″, all SATA performance levels, and all sizes (currently tested up to 4TB).

    Includes (and requires) its own 12V, 2.5A power supply, so it is fully self-powered and will work even with unpowered hubs and battery-powered hosts.

    No drivers required for installation, the dock uses standard USB mass storage class support already provided in Windows XP and later, Mac, Linux, Chrome OS, and some variations of Android.

    PLEASE NOTE: Compatibility of USB 3.0 hubs on the latest 2012/2013 Macs is still evolving, because of differences in Apple hardware and OS X USB stack. Applying the latest hub firmware and Apple updates are recommended. When in doubt, on the newest Macs we recommend connecting the dock directly to a port on the host machine.

Windows 8 and Intel USB 3.0 Host Controllers

[Note: As of Windows 8.1, we don't recommend replacing the in-box Windows USB 3.0 stack with the Intel Windows 7 stack, as described in this post. This post is being kept for historical background, but we recommend working with your PC maker and Microsoft on any remaining issues with the built-in Windows 8.1 USB 3.0 stack. Feel free to also comment below if problems remain.]

One of the new features of Windows 8 is the built in XHCI host controller software and USB stack. While this brings some benefits like UASP support, there are some devices that currently don’t work with the Microsoft stack on the Intel USB 3.0 host controller. This can be fixed by forcing Windows to use the Intel USB 3.0 host controller drivers instead of the built in stack.

*NOTE* These instructions are only for machines with an Intel eXtensible Host Controller. Look for the Intel(R) USB 3.0 eXtensible Host Controller under Universal Serial Bus controllers in Device Manager.

First, download the latest driver package from Intel. It’s currently at version and can be downloaded from the following link:

Intel(R)_USB_3.0_eXtensible_Host_Controller_Driver rev.

Once the download has finished, extract the .zip file to a known location.

Now download these two .inf files which have been modified to allow the Intel driver to install on Windows 8:

We are going to replace the existing versions of these two files with the ones we just downloaded. Place the files in the following directory of the unzipped driver package and click yes when Windows warns that we are over writing a file with the same name:


This will update these two infs with the modified versions that will allow the Intel driver to install on Windows 8 when the Host Controller and USB hub drivers are updated.

To install the Intel drivers in place of the in box XHCI stack, we’ll have to temporarily disable Driver Signing Enforcement. To do this press the Windows key + R and in the run box type:

shutdown.exe /r /o /f /t 00

Now make the following selections to boot into the Start Up Setting Screen

Troubleshoot — Advanced options — Start Up Settings — Restart

Then, when the machine restarts, select “Disable driver signature enforcement”. Your machine will start with Driver signing enforcement disabled until the next reboot.

When the machine restarts, open Device Manager (win + r, devmgmt.msc). Double click on the entry for the Intel(R) USB 3.0 eXtensible Host Controller and select the Drivers tab. You should see that the driver provider is Microsoft.

Now click “Update Driver” and then select “Browse my computer for driver software”.

Next choose “Let me pick from a list of device drivers on my computer”.

Next, select “Have Disk”.

In the Window that pops up titled “Install From Disk” choose “Browse” and navigate to the location where we replace the original infs with the two modified .inf files we downloaded earlier. Select iusb3xhc.inf and click ok.

Windows will warn that the driver is not signed and will require you to confirm the installation.

Once the installation is complete, reboot the machine following the same procedure as above:

shutdown.exe /r /o /f /t 00

Now make the following selections to boot into the Start Up Setting Screen

Troubleshoot — Advanced options — Start Up Settings — Restart

When the machine starts, select “Disable driver signature enforcement”. Your machine will start with Driver signing enforcement disabled until the next reboot. Once logged in, open Device Manager (win + r “devmgmt.msc”) and locate the entry under Other devices for an Unknown device, to find the correct one, double click on the entry for the unknown device view the details tab. Make sure it has the VID_8086.

Once you have located the correct device right click on it and choose “Update Driver” Choose “Browse my computer”, Windows will ask you to identify the type of device, scroll down and select “Universal Serial Bus Devices”.

Click next, choose “Have Disk”, “Browse” and select the modified iusb3hub.inf that we placed in the Intel(R)_USB_3.0_eXtensible_Host_Controller_Driver\Drivers\Win7\x64\ folder earlier and click ok.

Again, Windows will warn about driver signing, when the install is finished, reboot your machine.

When it restarts look at the driver tab for the Intel(R) USB 3.0 eXtensible Host Controller and the Intel(R) USB 3.0 Root Hub to confirm that you are now running the Intel drivers.

To return to the built in Microsoft USB 3.0 driver stack, use the uninstall drivers button from the driver tab in device manager. When it’s finished, select the Action menu of Device Manager and “scan for hardware changes” Windows should find the Intel USB 3.0 host controller and re-install it using the built in Microsoft XHCI stack.

Thanks to Ekko for his original work on this. Please comment below if you have any corrections or refinements. We’d also love to have comments mentioning the problems you were having, and whether the Intel stack solved them for you. Thanks!

New USB 3.0 Support Built-In to Windows 8

Microsoft is formally launching Windows 8 today. With all the talk about Windows 8 being focused on the UI, it’s easy to overlook developments that have been happening under the hood. Some important changes include the addition of a native USB 3.0 stack, UASP or USB Attached SCSI Protocol support as well as support for function suspend and remote wake-up. The new driver stack supporting USB 3.0 is loaded whenever a USB 3.0 device is attached to an xHCI host controller and is based on Microsoft’s Kernel Mode Driver Framework (KMDF). New features available to developers include:

  • Static streams for bulk endpoints — allows a client driver to open up to 255 streams in a bulk endpoint
  • Chained MDLs — can boost performance by avoiding buffering
  • Function suspend and remote wake-up for composite devices

With USB 3.0 users can expect the fastest performance for external USB drives to date, and if their hardware is UASP capable — the improvement can be even greater. UASP allows hardware that supports it to use command queing which enables the device to perform transfers in parallel. Function suspend and remote wake-up allow the operating system to utilize advanced power management features that are defined in the USB 3.0 spec. With the growing array of USB 3.0 devices available and backward compatibility with USB 2.0 and 1.1, USB 3.0 is bringing much better performance to what is probably the most ubiquitous hardware interface around.

Many Windows 8 systems are thin-and-light with room for only 1 or 2 USB ports. Most people have a lot more devices than that. Fortunately, one of the wonderful features of USB is a great architecture for supporting hubs which enable many devices to share one port. So a USB 3.0 hub like our Plugable USB 3.0 7 Port Hub with 4A Power Adapter is a great companion.

The increased throughput also allows a better user experience when connecting one of our USB 3.0 graphics adapters like our USB3-HDMI-DVI graphics adapter or our USB3-VGA graphics adapter. Another great match is our USB 3.0 Universal Docking Station. Featuring graphics, audio, and networking all managed by single DisplayLink DL-3700 chipset the UD-3000 also provides a 4 port USB 2.0 hub and a 2 port USB 3.0 hub. The added bandwidth greatly improves the performance of USB docking stations, and the UD-3000 performs accordingly with network intensive and video tasks.

Each USB 3.0 device such as the DisplayLink graphics solutions still requires specific device drivers, but with the underlying USB 3.0 host controller stack built in to Windows 8 there won’t be much difference to the user from USB 2.0 — except speed. Prior to Windows 8, different USB 3.0 host chipset vendors shipped updates to drivers for their host controllers that fixed bugs and added features. Thanks to Microsoft’s efforts, this function has been moved into Windows 8 so users will have one less thing to do when trying to get the maximum performance possible from their equipment.

You can get a lot more background on what’s new for USB in Windows 8 from the Windows USB Core Team Blog.

Any questions about Windows 8 and any Plugable products? We’d be happy to help. Post below, or email anytime. As always, we’re here to help!

Update: Plugable USB 3.0 PCI-e card upgraded to Renesas µPD720202 Host Controller

Our popular 2 port USB 3.PCI-e add-in card has been updated with the new Renesas µPD720202 Super Speed Host Controller chipset from Renesas. The µPD720202 is fully compliant with USB 3.0 and xHCI (eXtensible Host Controller Interface) 1.0 specifications and PCIe Gen2 system bus specifications.

Other improvements include:

  • Reduced power consumption in low-power mode to 4.5 mW, a reduction of 90 percent from our existing µPD720200 based product
  • Improvements to the data transfer processing circuit provide an increase in the effective data write speed of more than 40 percent over the µPD720200
  • The µPD720202 features reduced power consumption so supplemental power via a SATA to molex connector is not needed
  • Firmware download function eliminates the need for external serial flash ROM

Drivers for the new Plugable PCI Express to SuperSpeed USB 3.0 2-Port Expansion Card with the µPD720202 are different than for the µPD720200 based card. All Plugable PCI-e USB 3.0 cards purchase after 10/16/2012 have the new µPD720202 chipset and will require the new drivers. Both the previous and current versions are available at our Renesas driver page:
Plugable PCI-e USB 3.0 drivers

Any questions? We’d be happy to help. Post below, visit the support page for the product, or email anytime.

Where to Buy

Plugable’s New USB Keyboard for Kids

The newest addition to the Plugable family of products is the bright and cheerful Kids USB Keyboard! The fun and colorful design of this keyboard is sure to inspire and engage young computer users. Easy to read large keys and color coded system helps young kids learn their vowels, consonants, numbers and function keys. Purple for Vowels, Green for consonants, Orange for punctuation and Blue for editing, function and Microsoft Hotkeys; the Kids Keyboard helps children learn while the large keys make it easier to use, and more fun!

Kids Keyboard -- large keys

The kids keyboards has much larger keys than a regular keyboard.

The rugged construction from durable ABS plastic allows for wear and tear expected of any product for kids. Plug-n-Play compatibility makes it easy on the adults; No installation or setup necessary, no driver installations, all versions of Windows XP and up will detect and recognize the device instantly.

It should be noted that this keyboard has over-sized keys and should not be used for touch type learning.

Plugable USB Kids Keyboard (Extra Large Keys - Color Coded)... Product Details

Plugable’s UD-160 Universal Docking Station Arrives in Europe!

In response to the huge demand from our customers across Europe, we are launching the UK-EU versions of the Plugable UD-160-A Laptop Docking Station and the Plugable UD-160-M Multiseat Thin Client. They’re the same as the popular US versions but come with power adapters localized for UK and EU mains.

For details see:

The UD-160-AEU and the UD-160-MEU are interchangeable, with different descriptions for each use case.

They’re both available now on, dispatched by Amazon, with shipping to the following 27 EU-region countries:

UK, Germany, France, Spain, Italy, Belgium, Luxembourg, Netherlands, Ireland, Portugal, Austria, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, Greece, Hungary, Latvia, Lithuania, Malta, Poland, Romania, Slovakia, Slovenia, Sweden

Plugable USB 2.0 Universal Laptop Docking Station with DisplayLink DVI/VGA up to 1920x1080, Audio, E... Product Details

Troubleshooting the Plugable USB3-SATA-U3 Hard Drive Docking Station

The Plugable USB 3.0 SATA Hard Drive Docking Station is a convenient way to connect SATA hard drives to any computer with a USB port. It’s compatible with both USB 2.0 and 3.0 and either 2.5″ or 3.5″ drives. Becuase the drivers are included in all major operating systems it’s as simple as plug and play so there’s nothing to install.

If you do have problems, there are many different issues that can cause your SATA Dock to misbehave – among them are drive format, disk failures, and permissions issues. This troubleshooting guide will help you through the process of getting your USB3-SATA-U3 up and running at USB 3.0 speed.

Initial Setup –

The first step is to connect your SATA Dock to AC power and to an active USB port. With no drive inserted you should see the green light illuminated like this:

The Plugable USB3-SATA-U3 dock will light up green when power is connected.

Make sure the green light is on before connecting to the computer.

If your dock is not indicating power with the green light, stop here, contact us at We’ll be happy to help.

Choosing your cable —

Your Docking Station comes with both USB 2.0 cable and USB 3.0 cables. The USB 3.0 cable has blue plastic inside the connectors.

USB 2.0 connectors

The ‘A’ and ‘B’ ends of a USB 2.0 cable.

USB 3 connectors

The ‘A’ and ‘B’ ends of a USB 3.0 cable.

We’ll start with the USB 2.0 cable. Once we have everything working on USB 2.0 we’ll move up to USB 3.0 – if it’s available on the host computer. Connect the USB 2.0 cable to the docking station and to a known good USB port on your computer. To verify that the port is working, test with a simple device like a wired USB mouse.

Windows troubleshooting steps — click for Mac.

First power off the dock and insert the drive. The Plugable USB3-SATA-U3 Hard Drive Docking Station is compatible with both 2.5″ laptop sized drives and 3.5″ desktop sized drives. Be sure to line up the connectors inside the slot with the connectors on the drive and push the drive into the slot firmly until it seats on the connector.

Once your drive is installed, power on the dock with the switch on the back. After a minute or so, you’ll see an “installing new hardware” message and if the drive is recognized and mounted successfully you’ll see this:

Win 7 Sata Dock Installed

The Windows 7 message alerting you that the dock is ready for use.

Windows Auto Play dialog

Select Open folder to view files to access your disk.

If the drive is formatted and working properly, you’ll be presented with the Windows Auto Play dialog. You can click on “Open folder to view files” to access your drive.

If not, we’ll need to start the Windows Disk Management Utility so we can initialize our disk.

Open the Start Menu and type Disk Management in the search box (for XP type drvmgmt.msc) and press enter. This will start the Windows Disk Management Utility.

Windows Disk Manager

click on image to enlarge.

You should see the disk listed, probably as unallocated space. Right click on it and choose “New Simple Volume”. Follow the wizard to format and initialize your new disk. Once the wizard finishes, your disk will be available to Windows.

Simply open Windows Explorer, it will be listed under “Computer” in the list of available drives.

If your machine is equipped with USB 3.0, we can now safely eject the drive and reconnect it with the USB 3.0 cable to a USB 3.0 port on your computer. To do this click on the USB icon in the lower right of the screen and select “Eject MassStorage Device”. Using the USB 3.0 cable that came with your USB3-SATA-U3 Hard Drive Docking Station, connect your dock to a USB 3.0 port on your computer. Your USB3-SATA-U3 dock should now be operating at USB 3.0 speed. If you are having problems getting your docking station working on USB 3.0, first make sure it’s working on USB 2.0. This will verify that the drive is properly formatted and functional, the power supply is good and the USB 2.0 cable and port are both good. Contact us at if you have any trouble.

Mac troubleshooting steps —

Drive listed in Finder on Mac

Click on image to enlarge.

First, connect the dock to AC power and verify that the green light is on. Next, connect the dock to your Mac with the USB 2.0 cable. See the image above for the difference between the USB 2.0 and USB 3.0 cables. Insert your drive being careful it seats fully, and power on the dock. If the drive is formatted for Mac and working properly, it will show up in finder under devices. In this example the new drive is labeled “New Volume”.

Click image to enlarge.

If your drive is not detected, use Disk Utility to investigate. First check that the disk is showing up, then click verify. If the system is able to verify the disk it should be accessible to finder. If not, select Partition. Be aware that this action will erase any data that is currently on the disk. Choose a partition layout and select apply. Your new disk should now be available.

If your Mac has USB 3.0 ports available, you can now connect your dock with the USB 3.0 cable.

If you are having trouble getting your SATA dock running, contact us at Please feel free to comment with your thoughts, suggestions or experiences, thanks!


USB Gigabit Ethernet speed on Mac OS X

USB to Gigabit Ethernet adapters are especially useful for adding faster wired network capability to otherwise WiFi-only machines like the Macbook Air.

You can buy Apple’s branded 10/100 USB adapter — but price-wise, it will cost more than some gigabit adapters (like our Plugable USB Gigabit adapter). A gigabit adapter is also a nice upgrade for machines that only have a 10/100 ethernet port, but are connecting to a gigabit-capable network.

Because there’s often confusion about the rated speeds and actual throughput, especially when running 1000Mbps Ethernet over USB 2.0′s 480Mbps bus, we did some testing to establish a base line.

The test:

We installed the latest ASIX AX88178 Mac drivers for the Plugable Gigabit Adapter (currently v6.3.0). We used the open source network testing tool iperf running on a Mac Mini Server running 10.7.3 and a MacBook running 10.6.8. If you’d like to duplicate our tests, here’s a nice pre-compiled GUI version available here: JPerf-2.0.2.dmg. In order to isolate the adapters as completely as possible, we connected directly between two ethernet ports, set the address manually and ran iperf as both server and client in each direction. Remember that in order to get gigabit speeds, your entire network (including any routers in-between) need to be gigabit capable.

The results:

PCI-Gigabit Ethernet
USB-to-Gigabit Ethernet (Plugable USB2-E1000)
USB 10/100 Ethernet

* send/receive speeds to a 2nd machine running PCI Gigabit Ethernet

These are low-level performance numbers (raw TCP/IP throughput). Real world throughput like copying a file over the network will be substantially lower due to transport overhead and any bottlenecks on the network or on either side of the transfer.

Using a tool like iperf and isolating the ethernet adapters to a direct connection establishes a base line for data speeds. To further identify potential networking bottlenecks, introduce one network component at a time and rerun your tests to see how the throughput is effected by the increasing complexity.

For detailed instructions on installing Mac drivers for the Plugable USB2-E1000, see Howto: Installing ASIX’s USB Gigabit Ethernet Driver on Mac OS X Lion 10.7.

We hope these numbers are useful to set performance expectations. Have any questions? We’d be happy to help. Reply here or email anytime. Thanks!


Howto: DisplayLink USB Single Monitor on Linux

Unfortunately, Linux doesn’t support multiple graphics adapters the way Windows does, which means you can’t just plug in USB graphics adapters and expect them to extend your desktop (the good news is there is progress on this support).

What is possible, however, is running a single DisplayLink adapter, or several with a Xinerama or multiseat configuration — just as long as you don’t expect to use your main GPU at the same time.

The single-display case is relatively easy to set up, and we’ll cover that here.

First, make sure you’re running kernel version 2.6.35 or later (Ubuntu 10.10 or later). For older kernel versions, you’ll need to update udlfb and run a modified fbdev X server (not covered in this post). On these kernel versions, when you plug in your DisplayLink-based USB graphics device, you should get a green screen. This means that at the driver built into the Linux kernel is happy, healthy, and talking to the device.

Second, if you are running Unity Desktop in Ubuntu 11.04 or later, you’ll need to switch back to Classic Mode so you’re running straight X. Here’s how on Ubuntu:

Click on the power button in the upper right corner (mine looks like a light switch) and choose the last option, System Settings. Search for Login Screen, Double-click to display, Choose Unlock and enter your password, Select Ubuntu Classic as default session.

Third, if you’re running kernel versions between 2.6.35 to 3.1, enable the fb_defio option of udlfb. To do this, create or edit a file like

and add the single line

options udlfb fb_defio=1

And reboot (or run “sudo depmod -a” and unplug/replug your adapter). This will turn on defio (page fault change detection) support. This option is already enabled by default in kernels 3.2+.

Lastly, create an X config file called 60-plugable.conf (or similar) with the following contents and place it in /usr/share/X11/xorg.conf.d (on recent distros; on older distros, make this your xorg.conf):

Section "Device" 
  Identifier "uga" 
  driver "fbdev" 
  Option "fbdev" "/dev/fb0" 
  Option "ShadowFB" "off"

Section "Monitor" 
  Identifier "monitor" 

Section "Screen" 
  Identifier "screen" 
  Device "uga" 
  Monitor "monitor" 

Section "ServerLayout" 
  Identifier "default" 
  Screen 0 "screen" 0 0 

Note: if your main GPU creates a /dev/fb0 even when the USB display is not attached, then your USB display is probably getting assigned to /dev/fb1. In that case, change /dev/fb0 in the “Device” section above to /dev/fb1

Now, on reboot, you should (hopefully!) see your login come up on your DisplayLink USB attached display!

This kind of simple setup is useful for:

  • Testing or playing with your USB graphics adatper on Linux.
  • Embedded systems with USB but no GPU.
  • As a backup method when the main GPU or its driver isn’t available or working.
  • Systems where a USB graphics adapter enables higher modes (up to 2048×1152) than the main GPU screen.

Please comment if you have any trouble with this single display case. See our past posts for additional information about the DisplayLink Linux kernel driver and some more involved setups.

The instructed here work on all Plugable USB 2.0 graphics adapters and Plugable USB 2.0 docking stations and thin clients (and should also generally work on all DisplayLink based products).