2011 iMac best options for external SSD?

[mrianforest]

I've got an old (2011) iMac. FW800 and Thunderbolt connections on the back. I don't really want to open it up to fit an SSD nor can I afford to pay someone else to do it so I'm looking at running it off an external SSD.

The first idea was to use FireWire as I have a Lacie Rugged FW800 caddy but I've just discovered it's 100mb transfer at best so started thinking about using the Thunderbolt port instead.

Apple do a bi-directional Thunderbolt to USB-C dongle which looks like it might do the trick as I also have a spare WDD SSD with USB-C connection gathering dust in a drawer. I also have a 0.5m thunderbolt to thunderbolt wire so I think it should work?

 

[PaulD-UK]

That's a Thunderbolt 3 to Thunderbolt 2 bi-directional adapter, without power pass through, so it doesn't directly support the USB-C protocol.
Click on the Apple Support Page link on the link you've provided and you'll see this:
"This adapter is not compatible with USB-C ports that don't support Thunderbolt 3"

So it only works if you have self-powered TB devices both sides, like a TB3 dock, or powered TB3 single drive or RAID enclosure, if you use the TB2 port to connect to the computer.

In that mode it works very well with a 2011 iMac.

 

[USB3foriMac]

nor can I afford to pay someone else to do it so I'm looking at running it off an external SSD.

If you go Thunderbolt SSDs, you might as well pay someone to put a SATA SSD internal.
For cheaper external options, you can go for USB3 drives. If slow speed is enough, you can connect the to the USB2 port.
If you want faster speed, you could add USB 3 internally (see my thread in Signature), or you can use Thunderbolt-to-USB3 adapter, e.g. this one:

Kanex Thunderbolt to eSATA plus USB 3.0 Adapter

This one would give you eSATA at the same time; you could use it with a NAS with several disks.

 

[Fishrrman]

OP:

You're only options for thunderbolt to USB3 would be to find a used Kanex adapter (as in the post above this one), or perhaps find a thunderbolt2 dock (again, probably used).

Other than that, if you need more speed, it's getting to be time for a newer Mac.

 

[UFallingRock]

I recently upgraded my mid-2011 iMac (with a 1TB HDD) by attaching a Transcend 1TB external Thunderbolt SSD (the Storejet 500 model). I got it from Amazon for about $270: Transcend 1TB SSD

My drive access write/read speeds went from 50MB/s write and 75 MB/s read before to 350 MB/s and 375 MB/s with the external SSD. No more spinning beachballs and 2011 iMac feels like a new computer. I also used SuperDuper to clone the HDD, which made for an easy transition.