USB-C with Thunderbolt 2 port

You may be able to connect some usb-C devices to your USB3 port - of course this will be limited by the capabilities of the older port, but some devices just require an adapter.

If your mac has tb2 then it also has usb3 so that is probably the best course of action. Again, it will depend on the specific device.

Can you provide some more specific details? Generally speaking, they are pretty much incompatible. In theory, there are certain configurations and dongles that might seem to be able to establish a connection. But in practice, with real world devices that you are going to be able to find, you are unlikely to get them to work together. Without more details, all I can do is speak in these kinds of generalities.

For your information I have a new 2019 27' iMac, model ID:19.1. Running OS 10.14.4 & 5 Mojave. It has two Thunderbolt/USB-3 ports and into these I run Firewire devices. Two external FW hard drives and FW ADVC110 Digital Video/ Audio Interface for inputting to iMovie. Any VCR and any Camcorder Digital or Firewire. (Just a little secret. I still use iMovie 06 HD). Everything works perfectly.

Connection: From: TB/USB-3 I use a TB 3 to TB 2 adaptor, then TB 2 to FW adaptor to the external device and the other way around for reverse direction, device to computer.

These adaptors cost about $85 NZ so do yourself a favour and do all the thing you used to do with your old Mac.

Long live Mac's.

Sorry, correction to last post.

Should be Thunderbolt 3/USB-C Ports on new iMac but same adaptor configuration.

Conn, from TB 3/USB-C port to TB 3/USB-C / TB 2 adaptor, then to a TB 2/Firewire 800 adaptor to external device. You may need to use a FW 800 to FW 400 cable. Works just as good.

Not all USB-C interfaces support Thunderbolt signals on PCs at least. (All Macs with USB-C also do Thunderbolt.)

You are right that a USB-C to USB-A cable can be used and will provide USB connectivity between them - this runs at 5Gbps.

"Not all USB-C interfaces support Thunderbolt signals on PCs at least. "

TRUE

"(All Macs with USB-C also do Thunderbolt.)"

Almost true. The exception is the (now discontinued) 12" MacBook. These have only one single USB-C port and it is NOT Thunderbolt.

BigApple5 wrote:

why are there no adapters available?

Because there is practically no market for it. And the detailed specs on what is and what is not USB-C are cryptic, to put it very mildly.

In theory, you could just take a USB-C to Thunderbolt 2 adapter and turn it around. But as I and a few others can attest, it probably doesn’t work that way. In most cases, we have done this test using a bus-powered Thunderbolt 3 device, because that is about all there is. I don’t know if it would work with a self-powered Thunderbolt 3 device. But it turns out that self-powered Thunderbolt 3 devices are just about as rare as Thunderbolt 2 devices, if not more so. There are fancy USB-C hubs, but again, you are talking $300 to see if it works. Most people just stick with the devices they have for their older machines and use dongles for the newer machines.

My suggestion is this device: https://eshop.macsales.com/shop/external-drives/owc-drive-dock

It is USD $220, so less than $300. It has Thunderbolt 2 and USB 3.1 (albeit with an older connector). But you can put two of your own drives in it, including SSDs. I have one of these and it works great. Don’t compare Thunderbolt and USB by published speed alone. As you have discovered, there are some other potentially flaky aspects too USB. Thunderbolt is different. The operating system considers Thunderbolt to be almost an internal drive. When I connect via USB (even with this dock) I regularly get “unexpected disconnect” notifications, but not with Thunderbolt.

To be fair, $300 can get this device: https://eshop.macsales.com/shop/express-4m2

For this, you get almost internal SSD speed and it supports 4 SSDs.