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pineapple_prod

macrumors newbie
Original poster
Feb 5, 2021
2
0
Hello, brand new here and hoping someone can help me!

I have a 27" iMac, the 2020 model with 2 thunderbolt 3 ports on the back.

I somehow need to connect 2 San Disk Extreme Pro portable SSD's, and a Thunderbolt Display for a 2nd monitor.

I thought of this arrangement:

SSD Drive A plugs into 1st thunderbolt port on iMac
Thunderbolt Display plugs into 2nd thunderbolt port on imac
Get the thunderbolt 3 to thunderbolt 2 adaptor, and use it to plug SSD Drive B into the Thunderbolt display

How much speed will I lose?
Will it totally defeat the purpose of getting this high speed drive?
Is there a better way to do this- a hub of some kind?

Thanks much for any help anyone can provide!
 

pineapple_prod

macrumors newbie
Original poster
Feb 5, 2021
2
0
I actually haven't opened up the SSD's yet- waiting to determine which way I should go with this. I could easily return them, and get 2 internal drives for a raid.

I've gotten caught up in specs, and trying to maximize speed. I'm working with relatively small files, usually between 5M and 50M. Am I even going to notice a difference if I were to just plug one of the SSD's into a USB 3.0 port?
 

joevt

macrumors 604
Jun 21, 2012
6,979
4,267
Get the thunderbolt 3 to thunderbolt 2 adaptor, and use it to plug SSD Drive B into the Thunderbolt display
The SanDisk Extreme Pro Portable SSD is USB only, so it cannot be connected with an Apple Thunderbolt 3 to Thunderbolt 2 adapter.

Searching the web I could not find a San Disk Extreme Pro portable SSD that is Thunderbolt 3. Did I miss them? I found these: https://shop.westerndigital.com/pro...isk-extreme-pro-usb-3-1-ssd#SDSSDE80-500G-A25

Anyhow, the 27 inch 2020 iMac has USB 3.1 Gen2 which is 10Gb/s which you can plug these into the USB-A ports and get the full speed. If you want Thunderbolt 3 speeds (40Gb/s) you need thunderbolt 3 enclosures.
Only the Thunderbolt 3 ports can do 10 Gbps. No Mac has 10 Gbps type A ports.

Consider a Thunderbolt dock with a couple 10 Gbps USB ports (maybe an OWC Thunderbolt 4 Dock or Hub, or CalDigit Thunderbolt 4 dock). An Apple Thunderbolt Display only requires ≈8 Gbps so there's plenty of bandwidth from a Thunderbolt 3 port (40 Gbps) for two USB 3.1 gen 2 drives (10 Gbps each).
 

Fishrrman

macrumors Penryn
Feb 20, 2009
29,294
13,402
I looked up "Sandisk Extreme Pro" drives, and these DO NOT appear to be "Thunderbolt" drives.

Rather, they are USB3.1 gen2x2 drives.
Link:

As such, you cannot connect them to a tbolt2-to-tbolt3 adapter.
You need a USBc-capable port instead.

Also, the Thunderbolt Display -- isn't that thundebolt2 (and NOT tbolt3)?
I've never used one, so have to ask.
As such, wouldn't you need a tbolt2-to-tbolt3 adapter for the display itself?

Others... please jump in and correct me.

I'm thinking the best solution for the OP may be an external dock that has both USBc ports (for one of the drives), and a thunderbolt port (either tbolt2 or tbolt3).

Then connect:

Mac USBc/tbolt port ---> dock ---> display (with adapter if needed)
dock ---> first Sandisk drive (to USBc)
Mac USBc/tbolt port ---> second Sandisk drive.
 

joevt

macrumors 604
Jun 21, 2012
6,979
4,267
As such, wouldn't you need a tbolt2-to-tbolt3 adapter for the display itself?
The Apple Thunderbolt 3 to Thunderbolt 2 Adapter is bidirectional so it can also be used to connect a Thunderbolt 3 downstream device to a Thunderbolt 2 upstream device or host. I think all other Thunderbolt 3 to Thunderbolt 2 Adapters only allow connecting a Thunderbolt 2 downstream device to a Thunderbolt 3 upstream device or host.

The SanDisk Extreme Pro Portable SSD that I found was gen 2x1.

The one you found is V2 and is gen 2x2. I don't think there are any Thunderbolt docks that support gen 2x2. I'm not sure if macOS supports gen 2x2. You can get a gen 2x2 card and put it in a Thunderbolt PCIe expansion chassis to find out.
 

ght56

macrumors 6502a
Aug 31, 2020
839
815
Are you writing multiple/many 5-50 MB files at the same time or are you only writing one 5-50 MB file at a time?
 
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