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netmac

macrumors newbie
Original poster
Apr 5, 2017
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I have a bus-powered external thunderbolt 3 NVMe drive. I want to connect it to a 2015 iMac with thunderbolt 2. I have a TB2 cable and a TB3 to TB2 adapter. But TB2 port needs a self powered drive. Can I buy a TB3 hub like the one below to power the external drive?

- plug in the power supply to the TB3 dock
- plug in the TB3 drive to the TB3-in port
- plug in the TB3 adapter+TB2 cable+2015 iMac to the TB3-out port

Will this setup work?

TB3 to TB2 adapter

TB3 dock
 
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Can I buy a TB3 hub like the one below to power the external drive?
Yes, I have done this with Mid 2011, Late 2012, and Late 2013 iMacs.

I was able to run an external, bus powered TB3 Samsung X5 with NVMe as my boot drive on those Macs over TB1.

The connection:
iMac>TB1/2 cable>bidirectional adapter>TB3 dock>TB3 cable>External NVMe

I used a TB3 CalDigit Thunderbolt Station 3 Lite dock, but am unsure if the one you posted will work.
 
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While I think it is understood, maybe I should clarify that the TB3 dock needs to have an external power supply, or you would be in the same situation as the bus powered TB3 external drive.

For anyone else that is searching the forum for similar solutions for a TB3 drive on an older Mac with TB2 or TB3, if the TB3 drive has an external power source (not bus powered), then there is no need for the TB3 dock. You can connect the TB3 drive directly to the bidirectional adapter and it should work.
 
Yes, I have done this with Mid 2011, Late 2012, and Late 2013 iMacs.

I was able to run an external, bus powered TB3 Samsung X5 with NVMe as my boot drive on those Macs over TB1.

The connection:
iMac>TB1/2 cable>bidirectional adapter>TB3 dock>TB3 cable>External NVMe


I used a TB3 CalDigit Thunderbolt Station 3 Lite dock, but am unsure if the one you posted will work.

Thanks for the reply. What read/write speed (BlackMagic) are you getting from your setup?

I understand that the TB3 dock needs to have an external power supply.
 
What read/write speed (BlackMagic) are you getting from your setup?

Originally, I was getting 900MBps+ Read and 800MBps+ write speeds. I swapped the internal 500GB NVMe stick for a 1TB Samsung 970 EVO Plus stick, and that dropped the write speeds to 700MBps+, but read speeds stayed the same.

It was the fastest possible non-RAID boot drive option for my old TB1 iMacs. Having an internal RAID0 using SATA drives would be faster (1100MBps+ speeds).

Keep in mind that this is with TB1 (10Gbps), so your TB2 iMac could have different results.
 
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"Can I buy a TB3 hub like the one below to power the external drive?"

You could do this, but is it really worth the extra money you'll spend?

Is the nvme internal drive removable?
Might be easier to buy a cheap USB3.1 gen2 enclosure and use it that way for now.
 
"Can I buy a TB3 hub like the one below to power the external drive?"

You could do this, but is it really worth the extra money you'll spend?

Is the nvme internal drive removable?
Might be easier to buy a cheap USB3.1 gen2 enclosure and use it that way for now.

I have a 21" 2019 Mac (Mojave) with a very slow fusion drive. It is almost not usable. So I am using this TB3 external drive as the boot disk. It is 2 TB and has all my work files. BlackMagic rates it over 2500 MB/s read/write. It is much better now, but it is still not as responsive as the 27" 2015 Mac with an internal SSD SATA drive, rated around 600MB/s. Something is not quite right, but I am not sure what. So I want to be able to use the external drive on the 2015 Mac (High Sierra). I already have the TB2 cable and TB3-TB2 adapter. I should get a better speed with a TB2/3 setup than with a USB 3.1 gen 2 enclosure and I can use the TB3 drive between the 2 Mac without lowering the speed when connecting to 2019 Mac, particularly when it is not that speedy even with the TB3 drive:-(
 
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Resurrecting a slightly older thread, as I can't seem to find the answer to a question I have.
Pertaining using external stuff on my 2015 5K iMac (with the stupid 1TB fusion drive inside) through TB2 and a TB2/TB3 adapter.

It is clear that when you have an externally powered external TB3 drive, it will work through Apple's bi-directional TB2/TB3 adapter.
So normally below external Sabrent enclosure should work.

Now, the question I have is: if I would get a full docking station like the one below, pretty sure the built in nvme drives will work, but will all the other ports also work?


As I understand Thunderbolt 3 ports also carry USB signals, so would most of the stuff on that dock like USB ports, network port and SD card reader use the USB signals on that thunderbolt port/cable (and maybe Thunderbolt signals are only used for the NVME's and display signals), or is actually everything on that dock communicating with the computer through the Thunderbolt (TB2 in my case) link?

Or is that port really used as either Thunderbolt, or either USB? In which case indeed everything on that dock would use the Thunderbolt link to the computer!

All the above posts really talk about hooking up the external TB drive through a hub (to get it powered), and that tah seems to work with most of the docks, but nobody is saying anything at all about the other stuff on those docks!


---Edit---

Or maybe this dock, easier to get in Europe!

 
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