Anyone using a dock w/ their iMac?

Discussion in 'iMac' started by petercw2, May 15, 2019.

  1. petercw2 macrumors regular

    petercw2

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    #1
    I've been pondering the usefulness of a dock. With the ports on the rear hard to access and some of what I perceive are conveniences, they're not cheap. Just wondering if anyone else uses one with a iMac.
     
  2. mikehalloran, May 15, 2019
    Last edited: May 15, 2019

    mikehalloran macrumors 65816

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    #2
    There are USB-C/3.0 docks starting less than $20. I use a pair of these. There's no speed difference if between the two connections with an SATA III drive inside. SSDs are about 4x faster than 7200 RPM HDDs, of course. HDD platter/SSD drive speed is the bottleneck, not USB 3.

    [​IMG]
    and there are docks. I've no need.

    [​IMG]
     
  3. petercw2 thread starter macrumors regular

    petercw2

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    Mar 1, 2003
    #3
    Sorry, I should have been more specific than just a link.
    I was referring to the latter - a Thunderbolt/USB-C dock.
    thanks.
     

    Attached Files:

  4. codernova macrumors member

    codernova

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    #4
    Dock conveniences are on my list of things to get for my yet to be delivered new iMac. But it's very low on that list after a whole bunch of other stuff.
     
  5. jwhazel macrumors regular

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  6. mikehalloran macrumors 65816

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    #6
    You must mean Thunderbolt 3 over USB-C.

    USB-C is a plug, not a protocol. There are Macbooks with USB-C ports that support Thunderbolt 2 and some that do not support Thunderbolt at all. Likewise, there are USB-C docks without TB support of any kind.

    It all makes a difference.
    --- Post Merged, May 15, 2019 ---
    I bought this one for my iMac Pro. Though it plugs into the USB-C port, there is no TB3 support. Nice to have the card reader facing forward, too.
    https://www.amazon.com/gp/product/B078853NCS/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
     
  7. fisherking macrumors 603

    fisherking

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    #7
  8. petercw2 thread starter macrumors regular

    petercw2

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    #8
    Thanks. Yes, sorry if I’ve goofed up the terminology but basically looking to add convenience. The one Mike suggested that hangs underneath looks very sharp and I may try it. Thanks for the guidance.
     
  9. marzfreerider macrumors member

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    Canada
    #9
    I picked up a Satechi USB-C clamp hub pro. Color matches, sits flush and was very easy to install. More convenient for me than getting behind to access. Will be keeping an eye out for their USB-C stand, as it looks good as well.
     
  10. mikehalloran macrumors 65816

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    #10
    Yes, I like mine, too.

    The only issue I have is that it doesn’t support charging. There is only 2.5W available — half the power of an iPhone charger so, while it will charge an iPhone, it takes forever. More than enough juice to charge a Magic Trackpad 2 or Magic Keyboard while you’re using them, though.

    I have suggested to them that they make a version with active charging ports. It would have to be powered by a wall wort but I’d buy it.
     
  11. Fishrrman macrumors P6

    Fishrrman

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    #11
  12. mikey8811 macrumors member

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    #12
  13. theluggage macrumors 68040

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    Jul 29, 2011
    #13
    Thing to remember is - a USB hub always shares a single USB port on the computer between multiple devices with a maximum combined bandwidth of 5Gbps for USB 3.1g1 or 480Mbps for USB 2 devices. (or 10Gbps for a hub that does USB 3.1g2 - if you can find one). if you plug in multiple USB 2 devices to a USB 3 hub they'll still only be sharing a 480Mbps USB link to the computer

    Thats fine for mice/keyboards/printers/backup drives etc. but if you're plugging in multiple super-fast PCIe SSDs etc. either plug them directly into one of the USB 3 or USB-C sockets on the iMac or look at a Thunderbolt dock.

    Also USB-C hubs/docks with display connectors can't run 4k, 60Hz display and 5/10Gbps USB-3 devices at the same time - everything slows down to USB 2.

    Thunderbolt docks are a lot more expensive but contain extra USB controllers connected to the computer via 10-20 Gbps Thunderbolt, so should be better for driving multiple high-speed devices and 4k displays. Unfortunately, they never advertise how many USB controllers they contain (if you have one, it would be fun to dig into the System Report to see how the various devices are connected and whether they're using any internal hubs).

    Also, if you want to connect more than one USB-powered hard drive or similar, charge iPhones/mice/keyboards etc. get a USB hub with its own power supply - because, again, otherwise you're sharing the output of a single USB port between everything.

    This is part of the wider issue I have with the Satechi hub - it "uses up" one of the iMac's two USB-C/Thunderbolt ports (that could otherwise be used for connecting displays, Thunderbolt devices or 10Gbps USB devices) but doesn't offer any technical advantage over a hub connected to one of the regular USB-A ports (no extra power, no video, and as far as I know its single USB-C socket is just regular USB 3.1g1 with no bells and whistles). Anybody know if it will work off a USB-A plug with a USB C-to-A adapter?

    Again terminology is silly. USB2 is 480Mbps, USB 3.0 is 5Gbps and the USB-A ports (i.e. the 'regular' USB ports) on the back of the iMac are USB 3.0. If you're connecting a hub to USB-A then USB 3/USB 3.1 is irrelevant. So USB 3.1 is the new faster 10Gbps USB then? Nah, of course not!

    USB 3.1 gen 1 is - for most practical purposes - USB 3.0 "re-branded" and still the same 5Gbps. USB 3.1 gen 2 is the new, faster 10Gbps interface. So you can quite honestly sell a USB 3.1 hub that is still the same old 5Gbps speed. Read the small print to see if it supports 10Gbps (that's still rare) but if it connects to the Mac via an old-style USB-A plug then it won't, whatever (some PCs have USB-A ports that do 10Gbps - Macs don't).

    (Edit - the Amazon one you linked is just 5Gbps so for speed purposes it is no different from having a USB 3.0 hub connected via a USB-A to USB-C adapter).

    Don't worry folks - USB 3.2 and USB 4 are coming soon and then everything will be even more confusing!

    Not exactly wrong, but, oh! if only it was so simple, but in reality its a mess - for example some USB devices with USB-C connections are sold as "Thunderbolt compatible" because they work with the 'Thunderbolt' ports on computers, but if you read the small print they only use (slower) USB protocols. "USB3" is also widely misused to mean "USB A" (i.e. old-style) USB plug/socket (incorrect, but common).
     
  14. mikey8811, May 16, 2019
    Last edited: May 16, 2019

    mikey8811 macrumors member

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    #14
    Thanks for getting back - so it's all USB 3.0 anyway.

    If I plan on using 2x USB 3.0 drives and about 6 x legacy USB 2.0 drives, with the speed sharing and limitations you mentioned above, I am best off using 2 of the iMac's USB 3.0 ports for the full 5 Gbps of the USB 3.0 drives and then putting the 6 x USB 2.0 drives on the USB 3.0 hub correct?

    Also, both the Amazon and Anker one I looked at (https://www.amazon.com/gp/product/B00VDVCQ84/ref=ox_sc_saved_title_4?smid=A294P4X9EWVXLJ&psc=1) have 10 ports of which 3 ports are high current charging ports. The difference is the charging ports on the Amazon one also transmits data but the ones on the Anker hub doesn't.

    Is there a real difference in the way these charging ports otherwise work from the standard ones? All my drives are powered anyway so i will not be needing power from the hub.

    Other than the fact that Anker is probably a more reliable brand than Amazon, the Amazon hub has added flexibility in that it has a total of 10 outlets for full data use vs 7 in the Anker. The Amazon hub also has a choice of USB A or USB C connectivity.

    Also, 4 of the USB 2.0 drives are actually also Firewire 800 drives which I used daisy chained before. They are kind of wasted as USB 2.0 drives now but from what I understand, I would other wise have to get 2 types of costly adapter cables to be able to use them as Firewire 800 drives as before.

    Thanks
     
  15. mikehalloran macrumors 65816

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    #15
    Probably will but I've not bought an adapter to try out.

    I like having the USB-C connector on the front since I have a couple of peripherals with that plug. They are not TB devices of any kind, however.

    This is a similar hub that includes an HDMI port. That one needs to be plugged into USB-C for HDMI to work.
    https://www.amazon.com/gp/product/B07QGSW9LN/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
    All Macs with USB-C support HDMI over that port including those that do not have Thunderbolt.

    A SATA III SSD plugged into either the USB 3 or USB-C port will run at the exact same speed. Do not confuse marketing departments' nice round 6k/5k/10k numbers for specs or real world performance. The truth is that no SATA III Drive is as fast as USB 3 gen 1. Not one. The fastest HDD is a little bit over 1/4 that speed. I've tested these things. RAID Arrays,

    NVMe SSDs etc.? That's different. You want speed? Get a Samsung X5 and plug it into the TB3 port or a real TB3 dock.
    --- Post Merged, May 16, 2019 ---
    Now I'm curious. I've ordered a couple of adaptors to see.

    Note that there are two types. Those with the blue insert are USB 3 compatible and support 5G speed.
    https://www.amazon.com/Warmstor-Ada...+USB+Male&qid=1558028453&s=electronics&sr=1-6

    There are others with black inserts that only support USB 2 — that is a lot slower.
    https://www.amazon.com/Adapter-Base...+USB+Male&qid=1558028453&s=electronics&sr=1-3
     
  16. theluggage macrumors 68040

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    Jul 29, 2011
    #16
    They should support fast-charging on mobiles - unlike regular USB hub ports - but that only really affects mobile phones and tablets. Also the power stays on when the computer is shut down (these hub have their own power brick).

    That's not the point (anyway, unless you're using a Gen 2 device there's no difference between the USB you get from a USB-C port or a "USB 3" (you mean USB-A) one anyway - we're talking hubs - two or more half-decent SATA-III SSDs plugged into a hub are going to get close to that 5Gbps combined bandwidth limit (and USB 3's "5Gbps" is just as much rainbows and unicorns as SATA-III's "6Gbps" - you're rarely going to get that full bandwidth in real life). NVMe/PCIe SSDs that can push 5Gbps are getting more common now - and many use 3.1gen2 which very few hubs support.

    That would be interesting - its a neat-looking hub and being able to free up a USB-C for Thunderbolt or display would be a useful extra. I can't see why it shouldn't work in theory - it's only a USB-3 hub with a USB-3 interface to the computer.

    ...hmm. I think the Satechi on a USB-A port, leaving both TB3 ports available for Thunderbolt or video, would be a better solution. Bear in mind that if you connect a 4k@60Hz display to that, the USB 3 ports all degrade to USB 2 (an unavoidable property of USB-C).

    NB - note the review about those adapters being non-reversible - i.e. you have to plug the USB-C in the right way or it doesn't work - understandable for a cheap passive adapter that doesn't have all the reversible switchery.
     
  17. dimme macrumors 68000

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    #17
    I am using a CalDigit TB# dock. I need more USB ports and find I get better speed with a TB dock vs a USB hub. Yes it cost more but for my needs it is worth it.
     
  18. mikehalloran macrumors 65816

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    #18
    I wrote exactly what I meant and there was nothing for you to correct. I meant USB 3 as it is implemented on a Mac — we aren’t talking about PCs here. I meant USB 3 as opposed to USB 2 or 1.1 (Apple wired keyboards still have 1.1 ports, BTW). USB 3.1 is only available over USB-C.

    Yes, I know all about gen 1, gen 2 etc. but that’s nonsense since Apple does not support gen 2 over the type A plug. Let’s talk about the currently shipping hardware and accessories, Ok?
     
  19. theluggage macrumors 68040

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    #19
    It's not so much that you're wrong, it's that you're detracting from the point. The discussion was about hubs and their capacity to run multiple high-speed devices, not whether you should connect your single SSD to a USB-C or USB-A port.

    Your point is true in that few individual external drives will be seriously limited by being connected to a USB 3.1g1 port, but even SATA III SSDs can use more than half of the USB3.1g1 bandwidth so having more than one such high-speed device on the same port (via a hub) is not ideal. If you need to do that it's a case for looking into Thunderbolt docks rather than USB hubs. A Thunderbolt dock should do better than a USB hub even with two USB3.1g1 devices attached.

    Some currently shipping accessories with 3.1g2 over USB type A, which ought to work on Macs (if connected to the USB-C port):

    https://www.amazon.com/dp/B07FB94VJY/ref=psdc_3015402011_t1_B07DX9Z52F
    https://www.lindy.co.uk/usb-thunderbolt-c4/4-port-usb-3-1-gen-2-type-c-hub-p11211

    ...point is, there are also plenty of "3.1" hubs that don't do gen 2 (some of which connect via USB-C) and I'm sure if I hunted I could find a 3.1g2 hub that connected via the Macs USB-A socket (which wouldn't do 10Gbps on a Mac). So, yes, this stuff is relevant if we're talking about "which hub/dock to buy".

    (The Lindy one looks interesting - and is an example of what the Satechi ought to provide if its going to hog a USB-C - except for the silly short cable that's barely going to reach the ground on an iMac).

    Not sure if even having a 10Gbps capable hub would actually help in the case of multiple 5Gbps devices or if (as I suspect) it would run at the speed of the slowest 3.1 device. Which is where having a Thunderbolt device with independent USB ports would come in. E.g:

    https://www.amazon.com/StarTech-com...multi+channel&qid=1558091243&s=gateway&sr=8-2

    ...which ought to be able to happily run 2-4 fast SSDs and is substantially cheaper than a full-blown TB3 dock if you just want fast USB. Plus, it explicitly says that the ports are independent, unlike the TB3 docks which may or may not use internal hubs.
     
  20. mikey8811 macrumors member

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    Mar 23, 2019
    #20
    @theluggage I appreciate your comments here as you seem to be very well versed with USB and other connectivity standards.

    I have come across an issue with my base 27 in 2019 iMac that I didn't have with my old MacBook running Snow Leopard.

    One of the USB 2.0 drives, connected via a Belkin USB 2.0 hub to the USB-A 3.0 socket on the iMac seems to disappear from Finder and my desktop after a while. It still remains mounted in Disk Utility but I am unable to eject it there or via the diskutil command in Terminal. I can only power it off wherein it says the disk isn't properly ejected. Alternatively, I can shut down the iMac. Upon reboot the disk functions like normal and First Aid produces no errors. On my old MacBook, it can stay on and work for days and even weeks on end without a glitch. At other times. it remains in Finder and on my desktop but opening it, I get a blank and cannot access any files therein. Once again, I am unable to eject it there or via the diskutil command in Terminal. I can only power it off wherein it says the disk isn't properly ejected. Alternatively, I can shut down the iMac. Upon reboot the disk functions like normal and First Aid produces no errors.

    I presume it is not an issue of physical errors on the disk itself nor with the power supply and enclosure.

    Is this likely to be a USB 2.0 and/or USB 2.0 hub incompatibility with the USB-A 3.0 implementation on the iMac and/or Mojave?

    Will replacing the hub with a USB 3.0 one be likely to fix the issue?
     
  21. fisherking macrumors 603

    fisherking

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    #21
    is the belkin a powered hub? could be the drive is not getting enough power. try resetting the SMC on the imac (basically, power down, unlpug the AC from the imac, wait 20 seconds, replug). an AC-powered usb hub might otherwise be the way to go... (also, try plugging the drive directly into the mac, see if things are better... or not...)
     
  22. mikey8811 macrumors member

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    Mar 23, 2019
    #22
    Yes, the Belkin is a powered hub but I have been using it without the power connected even on my old MacBook because all my drives have their own power. I did connect the power to test if the issue would go away but it did not make any difference.

    I have also tried plugging it in directly - same thing.

    No issues at all without power on the hub and via the hub on my old MacBook.
     
  23. fisherking macrumors 603

    fisherking

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    #23
    so, even with the drive plugged directly into the imac, it disconnects? reset the SMC (& perhaps, if the problem persists, nvram... you can google instructions)...
     
  24. mikey8811, May 17, 2019
    Last edited: May 17, 2019

    mikey8811 macrumors member

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    #24
    No, it doesn't disconnect. It stays mounted in Disk Utility and I cannot eject it. But when i open the drive it is empty. please see screenshots:


    Screenshot 2019-05-17 at 7.02.49 PM.png

    Screenshot 2019-05-17 at 7.03.50 PM.png

    Screenshot 2019-05-17 at 7.04.34 PM.png

    I can only shut down my computer and when i reboot, it is normal and First Aid says all is fine

    Screenshot 2019-05-17 at 7.20.04 PM.png

    Before today, it would intermittently disappear from Finder and the desktop, in which case, i could not even open it BUT still stay mounted in Disk Utility just like I described above.
     

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  25. fisherking macrumors 603

    fisherking

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    #25
    sounds like it's time to replace the drive. get your files copied to a new drive asap (i would, if i were you)...
     

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