External SSD speed vs Thunderbolt 2 Dock on 2011 iMac

just my 10 cents if somebody finds this information useful. in the moment you have a imac and a apple laptop (> 2015 models) and you dont want to use cloud solutions for syncing your data across devices here is my setup. owc thunderbay 4 tb2 dock on the imac 5k 2016 and seagate goflex bus powered tb2 enclosure when mobile on a macbook pro late 2011. i have no problems with speed. you could have problems when video editing and such. i can fully recommend this setup and switching from one device to another takes about 2 min. the owc dock serves as raid/clone data backup so no cloud needed

"Yes" is the basic answer to your questions. This is what I have been using for awhile. I have a 2011 27" iMac that was modified by OWC with a SSD and the Apple hard drive in the iMac. 240gb SSD is the main system drive and the stock hard drive for storage. This link from OWC will tell you how to do this. http://blog.macsales.com/24915-splitting-your-data-an-alternative-to-fusion .

I use an OWC Thunderbolt2 dock. and have not seen any slow down of any drive connected to it.

SSD's normally max out around 480 to 500GBs which is well below the bandwidth of Thunderbolt, so there is little to no effect on speed.

I see you have a mid 2011 iMac, the OWC dock will let you now have USB 3.

I don't mean to sound like i'm pushing OWC, I am not affiliated with them, but I have used a lot of there products for over 10 years with no problems.

I have been looking at similar issues. Basically you're limited by wherever your bottleneck is located. If you have USB2 then that's where it is. You can get really, really fast drives but if it is all getting channeled through USB2 that's the speed you get. In my case I have been thinking about external data storage and figure I don't need more expensive 32MB cache, 6Gb/s, 7200 rpm drives because they will only get USB2 in and out of my '08 MacBook.

If you have a thunderbolt port, which you 2011 iMac has, the thunderbolt docks, any brand, will allow you to run USB3. My OWC Thunderbolt dock runs an external SSD at over 400Mb per second. Be sure to download the drivers from OWC or for what ever brand you get. You will not be able to use an external USB3 drive, through the dock, as a start-up drive though because the USB drivers for the dock do not load until the Mac has started up. You need a Mac that came with USB3 to use an external USB3 as a start-up drive.
I hope this helps.

It's all good jsa. After re-reading my post, I can see that I was not real clear about that. Good luck with the SSD install. Running the system on the SSD is like getting a new Mac. I have this set-up on both my iMac and a mid 2012 13" MacBook Pro (non-retina). Cold start to fully operational in 15 seconds!

Hello Gordon Grotts

I know your post is almost a year old but I exactly have the same configuration with js (whom you replied about upgrading to SSD and using it through tunderbolt as booting the OS.

I need to upgrade to SSD and I want to use is as an external drive to run my OS also. But English is not my native language so I want to be sure I understand you correct.

My iMac is Mid 2011, so it supports USB 2.0 and thunderbolt.
I am planning to purchase Sandisk Extreme Pro 480 GB and use it with thunderbolt dock (because of USB2 limitaiton on my iMac) but I cant figure out which thunderbolt dock to go with. I want to benefit the speed of Sandisk Extreme Pro SSD with thunderbolt .. Is that possible or I would be limited with USB 2 in my iMac?

Sorry if I sound like idiot but I am very kowledable on these topics.

Regards,

Enis

usb max out around 30MB/sec real world sustainable transferrate there is no way around that and even a sluggish 5400rpm 2.5" hd would be limited by that

Hello Rudegar,

I am sorry but I am not sure what you mean with your mean.

Although, after reading and searching and searching I think I have a better understanding of what Gordon Grotts mean.

Please correct me if I am wrong:

By going with TB Docks (such as OWC TB Dock 2...) even though my Mid 2011 iMac doesn't support USB 3, I will be able to benefit SSD speed thru thunderbolt connection to my iMac and can even boot up via SSD but not directly via External USB 3.

What I read from the reviews that OWC Thunderbolt Dock 2 has frequent disconnecting problem while working. Also checked Elgato TB Dock Station and some users are complaining that the display port is not working properly and the USB 3.0 ports are slower than expected. Now I am totally confused which direction to go for.

Any suggestions/advices or enlightening responses?

thanks,

Enis