Installing OSX from USB 2.0 vs. 3.0 - why is USB 2 recommended?

[SamSax]

The install instructions for El Capitan say the following:

"STEP 4: Install OS X El Capitan
You're almost done! All you need to do is boot from the USB drive and install! For best results, insert the USB in a USB 2.0 port."

I have a USB 3.0 Flash drive that runs much faster when inserted into the USB 3 port. Why would I want a slower install by using USB 3.0? What issues can occur using USB 3.0? Why is USB 2.0 recommended?

 

[Amylowellow]

The install instructions for El Capitan say the following:

"STEP 4: Install OS X El Capitan
You're almost done! All you need to do is boot from the USB drive and install! For best results, insert the USB in a USB 2.0 port."

I have a USB 3.0 Flash drive that runs much faster when inserted into the USB 3 port. Why would I want a slower install by using USB 3.0? What issues can occur using USB 3.0? Why is USB 2.0 recommended?

I did mine from the USB3 port no problem. But there are motherboards that USB2 just works better than the USB3 due to xHCI weirdness, etc.

Try USB3 1st and if it doesn't work use USB2 instead.

 

[SamSax]

Ok thanks! My MB is GIGABYTE GA-Z77X-UP, which seems to run fine with USB 3.0 (I did have some issues in the very beginning three years ago with my first install but can't remember exactly what that was).

 

[kiiroaka]

Some motherboard have USB3.0 that are on non-Intel controllers, like ASMedia. My ASrock even has a setting where it injects a patch if the ASMedia USB controller doesn't work correctly. The best bet is to look at your manual and see what ports are controlled by the Intel chip, which means that the USB port directly connects to the CPU, instead of going through a secondary controller. Some front panel USB3.0 ports are known to cause problems on certain mobos, just as USB3.1 ports are known to cause problems on certain mobos. Again, it's best to always use Intel USB ports.