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  • Grant Bennet-Alder Level 9 Level 9 (52,330 points)

    Ned, thanks for posting that!

     

    Is this Bus Powered as well?

     

    If so, you are adding fuel to the argument that a whole lot of USB3 devices may be taking liberties with the Specs, and Apple may only have a small problem, not a disaster.

  • Ned Soltz Level 2 Level 2 (465 points)

    Yes. The enclosure is bus powered.

  • keg55 Level 5 Level 5 (6,980 points)

    I don't have a Toshiba USB drive. Instead I have a Western Digital My Passport Essential. Both ports on my Retina are 3.0 and recognize the drive as USB 3.0

     

    The ports both show like below under System Report (USB 3.0 SuperSpeed Bus).

     

    Screen Shot 2012-06-28 at 4.18.20 PM.png

  • keg55 Level 5 Level 5 (6,980 points)

    Here's an update on my previous post.

     

    I plugged a USB 3.0 WD external drive into the left USB port and a USB 2.0 WD external drive into the right USB port. After performing a speed test with USB 3 -vs- 2, one of the Retina USB ports (right side) stayed at 2.0 and the other (left side) stayed at 3.0. Restarting the Retina did not resolve the issue. What DID resolve the issue for me was to keep the USB cable plugged into the right USB port and unplug the device from the cable; then plug the device back in. After doing that, the device showed up as 3.0 and now both ports are back to 3.0. Now I know what I will need to do if this happens again. It shouldn't be like this though.

  • cwkim Level 1 Level 1 (0 points)

    Fyi -- that's how it's supposed to behave.

     

    http://support.apple.com/kb/HT5172?viewlocale=en_US#8

     

    How do I get the best performance from the USB 3 ports?
    The first device you plug in will configure the port, so always connect USB 3 capable hubs or devices first.

     

    What happens if I plug in a USB 2 device into the USB 3 port first?
    If you plug in a USB 2 hub first, all devices connected or "daisy-chained" to that hub will operate up to the maximum transfer rate of USB 2 speed (480 Mbps).

     

    USB 3 devices are not activating or not appearing on the USB 3 bus. What could be wrong?

    Sometimes unplugging and plugging the device back in can resolve the issue.

  • keg55 Level 5 Level 5 (6,980 points)

    I totally understand both points 1 and 2. However, when plugging a USB 3.0 in first USB 3 should be used in the 'daisy chain'. However, that was NOT the case for me. I plugged the 3.0 device in first and the 2.0 second. I unplugged the 2.0 device out first; then unplugged the 3.0 device. So, the next time I plugged in my 3.0 device, I expected the 'daisy chain' hub to be 3.0 as defined in point 1 above. That didn't happen. I had to use point 3 abo ve to get the right side back to 3.0.

     

    So, I disagree this is how it is suppose to behave.

  • Joachim Frey Level 1 Level 1 (70 points)

    The Lexar Professional USB 3.0 Dual Slot Reader is also having issues.

    I got the following comment from Lexar support:

     

    Unfortunately we have discovered a compatibility issue between our Lexar Professional USB 3.0 Dual Slot Reader and new Mac computers with built-in USB 3.0. We have seen that using a USB 3.0 Powered Hub has solved this issue. Currently we're working with Apple in an effort to find a fix for this issue.

     

    JO

  • FatMac>MacPro Level 4 Level 4 (3,500 points)

    keg55 wrote:

     

    I totally understand both points 1 and 2. However, when plugging a USB 3.0 in first USB 3 should be used in the 'daisy chain'. However, that was NOT the case for me. I plugged the 3.0 device in first and the 2.0 second. I unplugged the 2.0 device out first; then unplugged the 3.0 device. So, the next time I plugged in my 3.0 device, I expected the 'daisy chain' hub to be 3.0 as defined in point 1 above. That didn't happen. I had to use point 3 abo ve to get the right side back to 3.0.

     

    So, I disagree this is how it is suppose to behave.

    So I can understand this, the first device in a daisy chain will determine the speed of operation of the devices further down the daisy chain, which has been the case with USB for quite some time. But the test you described didn't involve daisy chaining; rather, the left USB 3.0 port got a real USB 3.0 drive while the right USB 3.0 port got a USB 2.0 drive and both operated at their correct speeds. It sounds like you then moved the USB 3.0 device to the port the USB 2.0 device had been connected to and instead of getting USB 3.0 speeds, you got USB 2.0 speeds.

     

    KB HT5172 seems to apply to daisy chaining but "The first device you plug in will configure the port, so always connect USB 3 capable hubs or devices first" could also be understood to mean that port configuration is persistent, so what gets plugged in next is stuck with the setting that's already been established after the first device is removed. The solution you found is more subtle, first because "Sometimes unplugging and plugging the device back in can resolve the issue" is not offered as the solution to the problem you had, and second because "unplugging and plugging the device" could mean the device and cable or just the device (without your discovery, I'd just unplug the cable from the port, and that wouldn't work). Indeed, the issue you discovered isn't even acknowledged in HT5172.

     

    So one question is whether the computer's USB 3.0 port should be expected to negotiate anew every time a device is plugged directly into it, or must your renegotiating technique  be used? Another question is do the two ports negotiate their capabilities separately and retain the settings separately?

     

    Finally, if the port is set for USB 3.0, the device is also 3.0 and the device contains a bootable partition, can the computer be made to boot from the device at USB 3.0 speeds?

  • keg55 Level 5 Level 5 (6,980 points)

    Very good writeup.

     

     

    It sounds like you then moved the USB 3.0 device to the port the USB 2.0 device had been connected to and instead of getting USB 3.0 speeds, you got USB 2.0 speeds.

     

    You almost have it. I didn't move anything anywhere after the test. I simply ejected the right port's USB 2 drive leaving the USB 3 drive in the left port which was plugged in first to begin with. When I was done using that drive, I ejected it.

     

    This morning, I plugged the USB 3 drive into the left port and had USB 3 speed. Then I ejected it, unplugged it and plugged it into the right port and had USB 2 speed. That's where I noticed something wrong. Since I started the 'daisy chain' for the USB hub with a USB 3 device ALL ports should have been USB 3. My solution was to leave the USB 3 cable plugged into the right USB port and unplug the actual device and plug it back in. This solution fits the article's point below.

     

    USB 3 devices are not activating or not appearing on the USB 3 bus. What could be wrong?

    Sometimes unplugging and plugging the device back in can resolve the issue.

  • FatMac>MacPro Level 4 Level 4 (3,500 points)

    keg55 wrote:

     

    ...This morning, I plugged the USB 3 drive into the left port and had USB 3 speed. Then I ejected it, unplugged it and plugged it into the right port and had USB 2 speed. That's where I noticed something wrong. Since I started the 'daisy chain' for the USB hub with a USB 3 device ALL ports should have been USB 3. My solution was to leave the USB 3 cable plugged into the right USB port and unplug the actual device and plug it back in. This solution fits the article's point below.

     

    USB 3 devices are not activating or not appearing on the USB 3 bus. What could be wrong?

    Sometimes unplugging and plugging the device back in can resolve the issue.

    I guess that's where I get tripped up. Are both ports on the MBP being treated as being plugged into an internal hub rather than each having its own bus? If so, then I can see why that internal hub should be configured by whatever gets plugged into it first, thus affecting both ports equally, but your experience suggests that each is independent and is independently configured. Also, with two ports both in use, can "daisy chain" be said to be what's happening since the attached devices aren't really in line with one another, or does "daisy chain" include devices both connected to a hub but not to each other?

     

    As to the article's solution, I hate to sound like a politician, but its success would depend on what the meaning of device is understood to be. I've been using USB 3.0 on my Mac Pro with a PCIe card from OWC with hit and miss connection results for some time but I'd have understood "unplugging" to mean the plug from the USB 3.0 port, not the other end.

     

    And your WD USB 3.0 drive was both appearing and activating on the right port, it just wasn't going very fast, so their solution really didn't address your problem. That's why your solution is so important. Thanks for sharing it.

  • keg55 Level 5 Level 5 (6,980 points)

    Good first question. I can only assume both USB ports are independent depending on what device is plugged into it. Also, I can only assume that the article's reference to 'device' is the actual drive. That's what I'm referring to in my posts.

     

    Yes, when I had the issue this morning with the WD USB 3.0 drive plugged into the right port, it performed at USB 2.0 speed because is appeared/negotiated to the USB High Speed bus instead of the USB 3.0 SuperSpeed bus.

  • blackr41n Level 1 Level 1 (0 points)

    Read this https://discussions.apple.com/thread/4066311?tstart=0

     

    My seagate go flex thunderbolt is very slow tooo on NEW MBP speed is only 16MB/s

  • whatheck Level 5 Level 5 (4,080 points)

    I had some luck with these terminal commands. The drive mounted and showed the right speed in System Profiler. I recommend copying and pasting the commands into the terminal if you're not comfortable there.

     

    sudo mv /System/Library/Extensions/PXHCD.kext /System/Library/Extensions/PXHCD.kext.not

    sudo touch /System/Library/Extensions

     

    Reboot the system after running these commands.

     

    I had migrated from my previous machine and had this problem. I restored it, and it worked fine. I put everything back on and started isolating. This extension seems to be from when I had installed LaCie drivers on the old machine.

  • Shootist007 Level 6 Level 6 (16,645 points)

    All of this is just dumb/stupid on Apples part.

     

    I have PCs with USB 3 ports and none of them ever go to USB 2 speeds and stay there. Even if I plug in a USB 2 device the port is still USB 3. If I disconnect the USB2 device and connect a USB 3 device the port uses the USB 3 speed.

     

    This is just another FUBAR on Apple. With their implementation of USB 3.

    What is the point of having USB 3 ports if they don't always work at USB 3 speeds.

  • keg55 Level 5 Level 5 (6,980 points)

    No argument there, Shootist007. There should be no need for workarounds. It should "just work" per Apple's moniker.

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