Using FW drives on 2017 iMac

I need a bit of help here. I’ve just acquired a 2017 iMac. It has two Thunderbolt 3 ports,

I want to be able to connect a pair of FW800 drives to this Mac.
Searching Amazon etc., I can only find USB-C to MiniDisplay Port adaptors.
I already have MDP to FW800 adaptors on another mac and they work well.
Question is, will I be able to daisy-chain a USB-C to MDP and a DDP to FW800 and have the drives work?
That’s all. Thanks.

I think there is some misunderstanding regarding different connectors and what your existing adapters actually are.

The confusion comes from two facts:

  • Thunderbolt 1 and 2 use a Mini DisplayPort connector, but TB is not the same as MDP. An MDP port can only deliver DisplayPort video, but a TB port can also carry Thunderbolt data.
  • Thunderbolt 3 (and TB4) uses a USB-C connector, but TB3 is not the same as USB. A USB-C port can deliver USB data and DisplayPort video, but you need an actual TB3/TB4 port to provide Thunderbolt data.

You don’t have a “MDP to FW800” adapter. There is no such thing. You probably have a Thunderbolt 2 (which uses the same connector as MDP) to FW800 adapter.

Which is good. The missing adapter you need is a TB3-TB2 adapter. Note that this IS NOT a USB-C-MDP adapter. Neither USB nor MDP can carry Thunderbolt data. But a TB3-TB2 adapter should do what you want.

The only other possible issue is if your external drives are bus powered. Apple’s TB3-TB2 adapter can transfer data but not power. So your external drives will need their own power supplies.

(For everybody else, I just discovered that Apple no longer sells the TB2-FW800 adapter. So if you need one, you should move fast. I found some used ones on Amazon, but they’re quickly becoming impossible to find.)

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OWC says that they have them.

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Ebay is another source of obsolete connectors, mostly used. You need to be careful because some sellers may not know the proper name of the device, but at the moment they list 46 Thunderbolt to FireWire Adapters.

Thanks David,
The Adaptor arrived this morning and connecting to a MacBook Air running 12.1 the combination works well with a large G-Tech drive.
However (there’s always a however) the combination does not work on the acquired iMac running 12.6.9
Neither of the 2 Thunderbolt ports will see the combination.
I don’t have any other TB devices I can try.
( I notice that on both machines, system Profile says Thunderbolt/USB4)
Any thoughts?

I’m a bit late to the conversation, but are the FW drives in an enclosure that can be opened up? If so, have you thought of a multi-drive USB or FW3 enclosure (configured such that each drive is seen individually instead of in RAID mode)? Might be a bit pricy, but it’s future-proofed instead of messing around with (multiple) dongles and wondering if they’d work. An example:

I would think that simply transplanting the drives in to this enclosure without any kind of RAID wouldn’t mess up any of the data on them.


I connect a FW800 drive to my 2017 iMac by Apple’s Thunderbolt 3 to Thunderbolt 2 adapter chained to Apple’s Thunderbolt 2 to FireWire 800 adapter.

This same drive also has an eSATA port, and I’m thinking of getting an eSATA to USB adapter cable. I use a USB-C to eSATA cable for another drive and it works well.

Great news. So the adapter chain is working.

That sounds like there may be a problem with the TB ports themselves. Do the ports work for simple USB connectivity?

Some common things to try whenever built-in ports are behaving badly:

With luck, one of these will help.

Thanks again David.
Been a bit busy lately so sorry for the late response.
Unfortunately neither process turned on the ports. It looks as though I’m stuck with the normal USB ports only.
Bit of a bummer really as I had plans for this mac which have now gone out of the window.
Oh Well. Didn’t cost me anything except for that TB adaptor.

Which you should still be able to use with newer Macs for accessing those old hard drives.