U3 spins the disk non-stop even when mac is asleep. U3 does not sleep HDD at all.

I just received your U3 product and connected it to my Macmini6,1 with OSX 10.8.2 U3 is plugged into Macmini directly (no hub) and all patches applied and no matter how long I wait the U3 does not stop spinning HDD, it runs even when my main machine goes to sleep. I tried unmounting but that does not put the machine to sleep. Looks like power management on U3 is not working properly. I have tried the same drive in my FW800 IcyDock or Thermaltake USB2.0 dock. Both docks sleep my HDD either after 10 mins or if machine goes to sleep just fine.
I understand that you have been running into issues with Mac but I am hoping that after year plus with this product you were able to resolve the issue. I really need to know if this product will correctly or not. BTW, this is a fresh installation of OSX.

Hi Dima-

Thanks for posting with your issue.

I suspect that your mac has the energy saver option to “Put hard disks to sleep when possible” disabled.

To fix this, please go to your system preferences, energy saver, and check the box next to the drive sleep option so it looks like the attached screenshot. Close the window, and you should be good to go.

Please let me know if you find otherwise.

Best wishes-

Jeff Everett
Plugable Technologies !](https://d37wxxhohlp07s.cloudfront.net/s3_images/851614/disk%20sleep%20OSX_inline.png?1359672582)](https://d37wxxhohlp07s.cloudfront.net/s3_images/851614/disk%20sleep%20OSX.png?1359672582)

Hi, thanks for the quick reply. I certainly tried with this option checked and unchecked. I see absolutely no difference. It keeps spinning even when Mac sleeps. The green light goes off when Mac sleeps but drive keeps spinning. I waited for an hour and still no difference.

Hi Dima-

Can you please reply with the first 4 digits of the serial number on the sticker on the bottom of your U3? I’d like to see if another unit from the series has this same issue.

Also, thanks for verifying this is on the MacMini 6,1. We also have one of these so I’ll try to duplicate there. I assume you are connecting via the USB 3 cable supplied with the U3, NOT the USB 2 cable? If so, please try the USB 2 cable instead and let me know if the drive sleeps when the energy saver option is checked.

Thanks in advance for the extra info.



9918 are the numbers, I am using USB3 cable. BTW, I also noticed that this dock does cause me the BT problems too, meaning that mouse skips, etc. If I turn the doc off the mouse works great. I assume things are rough with Mac altogether. I will try USB2.

USB2 is the same problem, no sleep. Is your horizontal USB3 dock better since it uses a different chip? I am certainly not happy with this U3 thingy. BT interference is just abysmally bad… My USB3 Seagate Backup Plus does not cause any of that and sleeps like dead when it needs to.

Hi Dima-

Thanks for trying USB 2 as well. We were able to duplicate the sleep issue, and will look into ways to resolve it. For now, the only workaround we can suggest is to eject the disks and turn off the power switch on the dock.

As to the Bluetooth reception issue you mentioned, Intel has published a white paper with extensive details on interference with USB 3.0 and 2.4 ghz wireless signals. In short, this is a known issue, and the workaround is to locate the bluetooth device as far from any USB 3.0 ports as possible- even a few inches of distance can make a drastic difference. If you’re interested in the technical background on this here’s the paper: http://www.intel.com/content/www/us/e…

Best wishes-

Jeff Everett
Plugable Technologies

Thanks, Jeff. Unfortunately, that will not work for me at all. I read Intel’s paper and that is absolutely sad that they gave that paper as an excuse to blame product performance issues on USB standard. I have Seagate drive that is USB3 but it does not cause me any interference at all, and the cable on Seagate is even shorter cable than the one that you provided. Secondly, placing this dock far is not possible as the cable that came with it is short and given that paper, I have no idea what make of USB3 cable to buy.
Thank you for the honesty. This is a rare treat these days. Hope you can fix it. I ordered horizontal dock from Amazon but I think I will be canceling it now.

Note that there is a new firmware revision available since April (http://plugable.com/2013/04/22/usb3-s…). Unfortunately you will need Windows to install it, but I can confirm that the drive spins down when you put the computer to sleep and a few minutes after it’s been unmounted from a Mac. It’s still not to the point of other enclosures I’ve used that spin down the drive immediately when it’s unmounted, though.