Booting from USB 3.0

The main complaint with the USB 3.0 ports on the 2012 rMBP's, was that a 3.0 device would run at 2.0 speeds but it would still work. Port configuration was supposed to have been controlled by what kind of device you plugged into it first. Back then, I had raised the questions of was 3.0 speed booting successful and how to reconfigure the port back to USB 3.0 speeds. Recently, a poster said his reconfiguration solution was to plug the USB 3.0 cable into the port with nothing connected to it for a while and then connect the device to it. I'm still not clear about the booting question.

Because your USB 3.0 enclosure is recognized when not booted from, the connection itself is working. But booting is a very low level business and the problem may be the enclosure you're using, not the port itself. And it might make sense to try a different USB 3.0 cable first, preferably from a different manufacturer, since the Startup Manager is looking for something that it's not finding when you use the USB 3.0 (but not the USB 2.0) connection.

I can say that my rMBP 2013 boots from a USB 3.0 external, and if the external is connected after the port was used by a USB 2.0 device and the data transfer rate monitored from the start, it will begin at 2.0 speeds but quietly and quickly reconfigure itself to USB 3.0 and stay that way.

If you install the HD in the external USB 2.0 enclosure and have it mount when booting from the internal SSD, I assume you can select it in the Startup Disk control panel. If you then shut down, install the HD in the USB 3.0 enclosure and boot, what happens?

Which particular USB 3.0 enclosure are you using? Not all of them play equally well with USB 3.0 ports, and the original rMBP seemed to generate more USB 3.0 complaints than the 2013 version does.

In all honesty, when I started reading about the USB 3.0 connection issues in the forums, I held back from getting the rMBP until the 2013 refresh, which didn't generate the same kind of complaints. At the time, I wasn't even aware of the image retention issue, but that may have been addressed with the refresh too.

I don't think it's software, because software hasn't been loaded yet early in the boot process so the issue would need to be fixed with a firmware update of some sort. This thread mentioned a software update but there were still a lot of unhappy campers.

Since the problem may be your specific enclosure, I can say that this has worked for me. The only thing to watch out for is to use their video installation instructions on the website, not the booklet that's in the box.

One other thing occurs to me. It shouldn't make any difference whatsoever, but have you tried your booting tests using both of the USB 3.0 ports?

I have tried to install a Mac OS X 8.4 on a USB 3.0 stick from my macbook air 13-inch mid 2012 which has 2 USB 3.0 ports. The installation went fine, but when booting, the bootmanager would not see the USB stick installation of Mac OSX as a startup volume. I tried this, installing both with filevault enabled on the macbook and with filevault disabled, since I read somewhere that an installation with filevault on would not be bootable. In both instances, the USB stick would not be recognized as a boot partition on my macbook air, but it did boot my other macs, which don't have any USB 3.0 ports.

I then connected my USB stick to a USB 2 keyboard that was connected to my macbook air when in the bootmanager. It was recognized and I was able to boot from the stick.

My conclusion is that you cannot boot from a USB 3.0 device that is directly connected to a USB 3.0 port, but when it is seen as a USB 2 device, it is recognized as a boot volume.

I hope this helps.

Sodomydragon wrote:

...My conclusion is that you cannot boot from a USB 3.0 device that is directly connected to a USB 3.0 port, but when it is seen as a USB 2 device, it is recognized as a boot volume...

Actually you can because I just did. But as I mentioned above, I think the issue is the implementation of the USB 3.0 port itself and which one you (and the OP) have. The original USB 3.0 ports in the first iteration of the rMBP generated a variety of complaints and no clear answer about booting from one. That's why I held back until the 2013 version was released. Those ports behave properly, including booting from them, whether by external HD or flash drive. It looks like with the early implementation of the USB 3.0 ports, you just can't get there from here.😟

Same problem here.

I have a rMBP from mid 2012.

Did some tests with:

- Kingston USB3 64 GB G3 DT Stick

- WD 1TB USB3

Kingston directly connected to rMBP: not recognized at boot screen (both ports), so won't boot

Kingston connected to rMBP using a Aten usb 2.0 hub: recognized and able to boot, so my stick / image on stick is fine

WD 1TB USB3: recognized at boot screen and boots fine

So it looks like this is a USB3 (only) issue for some devices.

I have similar issues, but I have more evidence and conclusions...

Both a 2012 15" rMBP and a 2013 Mac Mini display the same problems. from any USB port. I have two self-powered 2.5" drives and one externally powered 3.5" drive albeith from the same manufacturer, Akasa.

The reason why I have multiple enclosures from the same manufacturer is that I went through extensive testing and found that these were the ones that worked the most reliably as a fast backup boot drive. They no longer work, so something must have changed. My bet is that this broke it: http://support.apple.com/kb/DL1609

My safety net workaround is to set up a SD card to boot in emergencies. You can now get 95 mb/s cards (SanDisk Extreme Pro), which I believe is faster than any USB stick.

But if anyone has more USB 3.0 enclosures that actually boot with these machines, please let us know what they are!

NB. I have submitted this as a bug to Apple.

With late 2013 retina 15", 10.9

the USB 3 Freecom docking station with a Barracuda HDD 2Tb 7200 works as a external startup disk.

Regards.

(HDD Barracuda ST2000DM001 & Freecom hard drive dock 3.0 )