Thunderbolt 2 male to USB-C male cable

The Apple adapter to convert Thunderbolt-2 <-> Thunderbolt-3 devices supports ONLY genuine ThunderBolt devices on each side, which your drive is NOT. it costs about US$50, and requries an added thunderbolt-3 cable, bringing the price to over US$100, and it will not work for your drive.

It's 2026, and in hindsight, we now know that Thunderbolt-2 today is good for DISPLAYS, and not much more. The market never provided wickedly fast Thunderbolt-2 devices other than displays.

To connect with all but the absolutely most demanding drives, use the USB ports implemented on your 2015 MacBook Pro, which provides USB-3 up to 5 Gbits/sec using a USB-A connector. Add adapters as needed.

If you have run out of USB ports, you need to add a USB Hub.

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Your dilemma pales by comparison to owners of the 2103 Mac Pro, which has SIX Thunderbolt-2 ports:

Angus McC wrote:

The SSD is a Crucial X10 https://www.crucial.com/ssd/x10/ct4000x10ssd9

Its port is USB-C – strictly, USB 3.2 Gen-2 2x2 (20Gb/s).

In that case your ONLY option is a USB-C to USB-A cable to connect it to one of the MacBook's USB ports. Or perhaps a USB Hub or perhaps an old Thunderbolt 2 dock that supports USB.

It will NOT work directly with the Thunderbolt port.

Angus McC wrote:

The SSD is a Crucial X10 https://www.crucial.com/ssd/x10/ct4000x10ssd9

Its port is USB-C – strictly, USB 3.2 Gen-2 2x2 (20Gb/s).

I want to connect it to the Thunderbolt 2 port on my MacBook (to free up the MacBook's USB-A ports (Apple calls them 'USB 3' MacBook Pro (Retina, 15-inch, Mid 2015) - Technical Specifications - Apple Support

I spoke to Apple Support today and was told that I can connect external drive to the MacBook's Thunderbolt 2 port...

You cannot connect that drive directly to the Thunderbolt 2 port on your Mac, even with the help of an Apple Thunderbolt 3-to-2 adapter. That adapter is bidirectional, but

• Only translates Thunderbolt protocol, and will not offer USB protocol on the USB-C side.
• Does not transmit power in either direction, which means that you cannot plug a bus-powered SSD into the USB-C side, even if it is a Thunderbolt 3 SSD.

There is a possible way to do it, but it is not practical. You would need to purchase

• A $49 Apple Thunderbolt 3-to-2 adapter
• A Thunderbolt 3 dock with its own power supply. Note very carefully, Thunderbolt 3 and with its own power supply. Thunderbolt 4 and 5 accessories are not backwards-compatible with Thunderbolt 1 and.2 hosts, and unpowered docks will not work for the same reason that bus-powered SSDs will not.

Other World Computing once sold such a bundle as a "Thunderbolt 2 docking solution." It is now discontinued, but it might be possible to roll your own. Even if you do, it's almost certain that you will not get USB 3.2 Gen 2x2 speeds and that your SSD will fall back either to USB 3.1 Gen 2 speed or to USB 3.0 speed.

Basically, you should keep using the USB-A ports on your MacBook.

Exactly what SSD drive is it? (Make & model number, please.)

There is no "thunderbolt 2 male to USB-C" cable.

Your 2015 Retina MacBook supports Thunderbolt 2 and USB 3.0.

First thing is to determine what the drive supports ... TB2, TB3, USB 3.x etc. Most likely if it only has a USB-C interface it probably does not support Thunderbolt 2. If it is a Thunderbolt 3 SSD you would need a Thunderbolt 3-to-Thunderbolt 2 adapter plus a TB2-TB2 cable (male both ends).

Alternatively, if the external SSD drive supports USB 3.x and only has a USB-C connection you could use a USB-C to USB-A cable to connect it to one of your MacBook's USB ports but the speed will be limited by your MacBook's USB 3.0 (5Gbps) top speed.

Chiming in here... that USB hub in your pic is in fact quite old. From the look of design style and the white components there in the plugs, I suspect it's only USB-2 capable. This is fine and dandy for keyboards, mice, printers and scanners, but not so much for a fast, modern storage device as your Crucial SSD.

That hub will be a severe bottleneck regarding file transfer speeds. Your MBP supports USB-3 and much faster data transfer rates than USB-2.

MacBook Pro (Retina, 15-inch, Mid 2015) - Technical Specifications - Apple Support

You bought a nice SSD, don't throttle it with an old hub.

Modern hubs/docks are not expensive. For example: Acer USB Hub 4 Ports USB-3 - Amazon

In general, USB-3 connectors that are rectangular use a BLUE insert (expect for Apple, who ignores that color coding).

USB-2 can be distinguished from USB-3 by looking inside the connector.

USB-2 has exactly four conductors:

USB-3 may have those same four, plus five more deeper inside the shell:

You’ve told us about the solution proposed, but less about the underlying problem and related background.

Seems not enough ports on some newer Mac, and plans to use an older Mac as a network-attached storage (NAS) file server?

If so, and as an alternative to cabling directly and then (presumably) serving the files, do you have any USB ports in your Wi-Fi router, or some unused x86-64 PC-compatible box or Raspberry Pi box you can repurpose as a NAS?

PS: An SSD via gigabit Ethernet (GbE) is going to be limited by the GbE, if not yet less.