Changing USB host controller on MacBook Air from high-speed to full-speed?

Question

Here's my situation; I have a 2011 MacBook Air running Windows 7, and I'm looking for a way to change the USB host controller or hub's speed from high-speed (480Mbps) to full-speed (12Mbps).

I know high-speed is backward compatible, but I need the controller or hub itself to run at full-speed, since I'm testing some 433MHz radio hardware that gets some nasty interference from USB operating at high-speed.

On a regular PC I can access the BIOS and configure the USB hardware there, but on a Mac it's a different story.

Any help is appreciated!

Answer 1

If you were to force the USB connection to 1.1 outside of your Macbook, would that work? You could purchase a USB 1.1 hub which would force anything you connected to it to be limited to full speed. Your port/hub at the Macbook would still be high speed, but nothing would be going into the port at high speed. That Hub I linked to is powered, but there are unpowered 1.1 hubs available as well, like this one.

Answer 2

I did a bit of research and I have some proposals -- please let me know if they can apply to you. Please keep in mind that I'm not an expert in USB devices (specially at such low level).

• I've seen that in VMWare Player you can choose to emulate USB 1.1 or USB 2.0 ( see http://www.vmware.com/pdf/vmware_player40.pdf, section "Configuring a USB controller") -- maybe you can setup a Windows virtual machine and enable only USB 1.1 support ;
• at least for Windows XP, you can disable the USB 2.0 driver forcing thus USB 1.1 (see for example http://forums.ni.com/t5/Multifunction-DAQ/How-can-I-force-the-USB-6216-to-talk-USB-1-1-rather-than-USB-2-0/td-p/981644). I think that something similar can be done with Windows 7 too -- some months ago on my Macbook I had some driver problems and my USB ports became quite slow, maybe for missing/misconfigured USB 2.0 drivers.
  For the sake of completeness, it seems you can do something similar also for Linux: http://forums.fedoraforum.org/showthread.php?t=88047