Hey All,
I think I figured this out. I was having the same problem with my onboard usb 3 drives ejecting or just stopping mid transfer when transferring large amounts of data. I've done a lot of digging since then and have tested my current setup to the point I feel I can share and be (mostly) confident.
I'm on 10.10.4 - The problem followed me into Yosemite. I did install the 1.2.7 Generic USB Drivers For Yosemite, but that alone did not solve my issue. But what seems to have are some bios settings:
- Peripherals > Device Config > xHCI Hand-OFF > ENABLED (the default, but good to check)
- Peripherals > Device Config > EHCI Hand-OFF > ENABLED
The default on EHCI was disabled. I believe this is what made the difference. I would try this before updating to the 1.2.7 Generic USB Drivers. Might need to do both, but you for sure need to Enable EHCI Hand OFF.
I got this information from
envoy510 at a Wordpress site. I tried to post a thank you but it wouldn't let me.
Hope this can help others!
jb