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Level 1

7 points

USB 3.0 device only works after connect a USB 2.0 in other port

Hi all,

Since update to OS X El Capitan, the system only detect mu External HDD USB 3.0 if I connect a USB 2.0 in other port (like a pen drive).

If I use USB 2.0 cable in the same HDD, it's detected by the system with no problem.

Attempts to solve this problem:

- Completely reinstalled OS X, without restore a Backup;

- SMC Reset;

- Replace the cable of HDD (I'm sure the HDD and cable are working well, when I plug it in Windows machine, it detects normally);

- Using OS X Yosemite the problem disappear.

This is not a hardware problem, after connect USB 2.0 and make the external device (3.0) to work, the transfer rates exceeds 100MB/s (USB 2.0 cannot do the same).

Some suggestion? I have this problem since the first public beta of OS X El Capitan.

Thanks....

MacBook Air (11-inch Mid 2012), OS X El Capitan (10.11.3)

Posted on Jan 22, 2016 5:45 AM

Best reply

MrPCowell

Level 1

8 points

Posted on Aug 13, 2017 11:36 PM

There is a known issue with certain Macs or OS and USB3

I work in a school, and we are just about to replace about 200 sets of USB headsets because they don't work on Macbook Airs. If we run them through an adapter they are fine, on older Macbook Pros they are fine, and on a Windows machine running USB3 they are fine.

There are also other USB2 devices we have that no longer work such as MIDI interfaces and keyboards.

Be great if anyone can find a solution to this.

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16 replies

EcoGreg

Level 3

876 points

Feb 3, 2016 7:51 PM in response to Marianco1

Hi Mariancol

Not saying anything wrong with getting info from a Hackintosh site, "If You Know What Is Going On", but for folks who need "It Just Works" then info there may not be useful.

Been hacking Macs, Atari, Windows, Linux since the mid 80's

Built a few myself and when I "hacked/,modified" my 2006 MP1.1 to run Mavericks/Yosemite, I went to these sites for info. Still wouldn't send noobs there for a purely Mac OS issue.

There may very well be issues with USB3 on Macs. In truth, Apple has never really been Great with USB3 and other protocol implementations.

Are there issues with new USB3 drivers? Don't know.

I find lots of problems relate to people using Migration Assistant over and over again since Tiger or earlier. Talk about problems!

This USB issue has tickled my interest, so as I have time I intend to pursue the matter, including looking at "Hackintosh" sites and the technical sites/forums. I agree they can be useful for details/insights. After all, injecting kexts, and other files is par for the course for "Hackintoshes".

I'll stand by my statements on UASP tho.

Peace, Greg

USB 3.0 device only works after connect a USB 2.0 in other port