Anyone using a dock w/ their iMac?

[theluggage]

Before today, it would intermittently disappear from Finder and the desktop, in which case, i could not even open it

I've seen some comments about USB 2 devices not working properly in USB 3 ports - but they're usually down to driver problems on windows PCs and the suggested solution is usually connecting via a USB 2 hub... USB isn't a perfect world.

However, as @fisherking said, any well-used USB 2.0 hard drive in 2019 is probably about due for retirement.

 

[mikehalloran]

I've seen some comments about USB 2 devices not working properly in USB 3 ports - but they're usually down to driver problems on windows PCs and the suggested solution is usually connecting via a USB 2 hub... USB isn't a perfect world.

That's a big issue with Macs and USB 2 audio interfaces, too. Often, a hub is the solution. This was part (all?) of the T2 problem with certain USB 2 audio interfaces on iMac Pros, 2018

USB 3 is not backwards compatible with USB 2/1.1. It's a different protocol carried over a different cable—2 cables cannot carry 3 and a 3 only cable (usually has the flat connector) cannot carry USB 2/1.1. A 3+2 cable is actually 2 cables in 1 with only the ground in common. It's only recently that Intel was able to resolve both in the same controller.
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Is there a real difference in the way these charging ports otherwise work from the standard ones?

Absolutely. They have a separate power supply from a wall wort. They will supply charging power when the Mac is off.

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.

Unfortunately, I have tried many Belkin hubs over the years with this exact issue. I don't know what firmware chip they use but it is not Mac friendly.

The Amazon Basics powered hubs work well for me. Some of them are sold under different names at OWC at a higher price.

There's a conversation on another thread that states the USB-C connector on the Satechi clamp hub referenced earlier only works in one direction. Absolute nonsense. BTW, it works the same through one of those USB-C to USB 3 connectors.

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

I got a pair in earlier today and tested it. The Satechi cable is short making the fit really tight so, if you want to do that to save a TB3 port, a 6" USB-C or USB 3 extender cable is recommended (I have a 12" USB-3 extender and used it for the test). As I have an iMac Pro with two side monitors, I have two extra TB3 ports.

 

[mikey8811]

Absolutely. They have a separate power supply from a wall wort. They will supply charging power when the Mac is off.

My drives are powered and have their own power blocks or wall warts. I can use them without the turning the power supply of the hub on. Conversely, am I able to use them without their own power supplies but with the hub power turned on? I am guessing it doesn't work this way around.

Unfortunately, I have tried many Belkin hubs over the years with this exact issue. I don't know what firmware chip they use but it is not Mac friendly.

The Amazon Basics powered hubs work well for me. Some of them are sold under different names at OWC at a higher price.

There's a conversation on another thread that states the USB-C connector on the Satechi clamp hub referenced earlier only works in one direction. Absolute nonsense. BTW, it works the same through one of those USB-C to USB 3 connectors.

Funnily, the same drives worked faultlessly on the same Belkin hub for as long as I have had my 2008 MacBook running Snow Leopard.

Given it is a USB 2.0 hub running a USB 2.0 cable to a USB 3.0 port, I thought getting a USB 3.0 hub running a USB 3.0 cable to a USB 3.0 hub may resolve the issue. I think I will try out the Amazon hub.

By the way, a lot of these hubs like the Satechi are available on AliExpress for a lot less. They look like they are from the OEM manufacturers so I guess they are reliable. I just can't find one similar to the Amazon 10 port one with 3 carhoing ports that can transmit data too.

 

[mikey8811]

The Amazon Basics powered hubs work well for me. Some of them are sold under different names at OWC at a higher price.

Hi

This one comes in USB C and USB A variants

https://www.amazon.com/gp/product/B...8081e145e35&pf_rd_r=HWASB5222QM3HAYK5RQW&th=1

I presume even with the USB C variant you will only be getting the 5 Gbps USB 2.1 ver 1 speed even though connecting through the Mac's Thunderbolt output?

So does it make sense to pay slightly more for the USB C version?

 

[theluggage]

I presume even with the USB C variant you will only be getting the 5 Gbps USB 2.1 ver 1 speed even though connecting through the Mac's Thunderbolt output?

It's a USB 3.1 gen 1 hub. Max 5Gbps. The specs on the site are pretty clear. No practical difference from any other USB 3 hub.

So does it make sense to pay slightly more for the USB C version?[/QUOTE]

Look carefully at the last-but-one photo on the site that shows what's in the box for each version: they're both exactly the same USB 3 hub with an old-style USB-B 'input' socket. One comes with a B-to-A cable, the other with a B-to-C cable. It shouldn't make any significant difference how you connect it.

• If you might want to connect Thunderbolt devices or external displays in future, get the USB-A version and leave both your TB3 ports clear for the future.
• If you need all the old-style USB-A you can eat, get the USB-C version to leave all 4 of the iMacs own USB-A ports open.
• Don't sweat it because if you change your mind you just need to swap the cable - and you can do the same with any other USB3 hub that you might prefer over this one.

Don't pick this one specially because it has a USB-C "option"!

Honestly, the only thing I'd look for particularly in this type of hub is a detachable cable - the short 'captive' cables on some hubs will barely reach the desk from an iMac socket, and you can swap a detachable cable for the appropriate C or A cable without resorting to dongles.

 

[mikehalloran]

So does it make sense to pay slightly more for the USB C version?

Nope — unless you have a peripheral that can take advantage of 3.1 on a Mac. Other than certain RAID arrays, nothing comes to mind. No SATA drive can. These don't support Thunderbolt 3.

Don't pick this one specially because it has a USB-C "option"!

Yep

Honestly, the only thing I'd look for particularly in this type of hub is a detachable cable - the short 'captive' cables on some hubs will barely reach the desk from an iMac socket, and you can swap a detachable cable for the appropriate C or A cable without resorting to dongles.

Although a good idea, If the cable is long enough, even that wouldn't bother me.

You can get small USB-C to USB 3 adapters
https://www.amazon.com/Warmstor-Adapter-Converter-Support-Charging/dp/B073H1QVJZ/ref=sr_1_7?crid=3AYZZBRQ623R4&keywords=usb+c+to+usb+3.0+adapter&qid=1558993170&s=gateway&sprefix=usb+c+to+usb+3,aps,202&sr=8-7

and vise-versa
https://www.amazon.com/AUKEY-Adapter-MacBook-Chromebook-Pixelbook/dp/B01AUKU1OO/ref=sr_1_13?crid=3AYZZBRQ623R4&keywords=usb+c+to+usb+3.0+adapter&qid=1558993268&s=gateway&sprefix=usb+c+to+usb+3,aps,202&sr=8-13

 

[mikey8811]

Don't pick this one specially because it has a USB-C "option"!

OK that was the selling point as I thought USB C is more stable than USB A. If that is the case I may as well pay slightly less for USB A.

Honestly, I haven't been impressed with the USB A 3.1 v 1 implementation in the recent iMac - drives unmount by themselves or become unresponsive for no apparent reason. The guy at the local Apple repair shop tells me that it is a common occurrence. I do miss Firewire. i know we have Thunderbolt now but those drives are crazy expensive.

 

[theluggage]

OK that was the selling point as I thought USB C is more stable than USB A. If that is the case I may as well pay slightly less for USB A.

Well, the "USB 3" on the iMac's 4 "USB A " sockets is from the USB 3.0 controller provided by the CPU chipset, while the "USB 3" on the 2 USB-C/TB3 ports is from the (newer) USB 3.1 controller provided by the Thunderbolt 3 controller chip, There should be no practical difference between 3.1 snd 3.0 on a 5Gbps device, but I suppose it is possible for them to be differently buggy... However, any USB 3 device connected to the USB-C port gets the "3.1" controller, even if its a USB-device with an adapter.