SDXC as a backup option?


macrumors newbie
Original poster
Apr 1, 2019
Hey all

While awaiting my new iMac with 512gb SSD I was thinking about backup options.

I'd be using Superduper to clone the drive and initally thought I'd go for the Samsung T5 500gb as it seems pretty well recommended on here.

I noticed that the iMac will have an SDXC drive and was wondering whether that is a feasible backup option if I put a 512gb card in there and simply leave it in. I never use this slot on my current iMac and thus was thinking if I could utilise it I wouldn't have to worry about cables and the like with an external.

Is there anything inherently wrong with an SDXC backup approach via Superduper. ie. it would be very slow or unreliable.

(I know it will be a decent bit more expensive to buy than the Samsung T5 - e.g. £200 versus £100 for the T5).




macrumors 68040
Dec 1, 2006
Cedar Rapids, IA. USA
Usually backup is a "background task" where speed is not an issue, so a cheap hard disk will do ... even a bus-powered portable USB3 drive velcro mounted to the stand will work.

As for the SD card slot on the back ... I have a 128GB SD card in mine with my iTunes music files stored there. Saves space on the fast and expensive internal SSD drive.

I have an external, easily accessible card reader for my camera SD and CF cards.


macrumors 6502
Sep 9, 2008
I also use a Samsung 500GB T5 for backup. I used Carbon Copy Cloner and it starts up/runs great on it (late '12 27" iMac). The only thing is that I have to hold down the 'option' key at startup and manually choose it to startup using it instead of the stock Fusion drive. I can't seem to get it to show up in Startup Disk control panel.

One thing I want to try is using a high capacity SDXC card to clone a basic/fresh MacOS installation onto, and see if it will startup on it.


macrumors regular
Jan 9, 2013
Just to add some more info here, most SD cards are going to be able to do 100 MB/s read and 50 MB/s write (though some may approach 100 MB/s on the write). The Samsung T5 external SSD is rated for 540 MB/s, with real world tests putting it around 450 MB/s for both read and write.

Note that MB/s is megabytes per second. Data speed may also be listed as mbps, which is megabit per second. Divide "bit" by 8 to get "byte".

I think the T5 is the better bang for your buck. But I can certainly see where a less obtrusive SD card could be attractive if you don't care so much about the speed.


macrumors G4
Jun 27, 2007
Central U.S.
Thanks everyone - I think a T5 it is.
I love the T5 and they've come down so much in price. It's light enough that you can just thread it through the hole in the back of your iMac stand and it just hangs out there on top of your other cables. You can also put a dot of velcro tape on it and on the back of your iMac and mount it that way if you prefer. I'm thinking about doing that, which would also hold the T5 in place in my camera bag which has velcro friendly side panels. I'm thinking about picking up another T5 as well to store my Steam Library so I don't have to partition so much of my faster internal SSD for Windows. I might even try one of those hacks to get Windows to boot from an external drive so I can leave bootcamp off my machine entirely.


macrumors 6502
Sep 9, 2008
The T5 is great. My only regret is not getting the 1TB version instead of the 500 GB. Stick that sucka on the back of your iMac with velcro stickers and a shorty cable and nobody even knows it's there. Amazingly small and light!


macrumors 68020
Dec 14, 2010
I might even try one of those hacks to get Windows to boot from an external drive so I can leave bootcamp off my machine entirely.
This would be great - I didn't realise it was possible?...….


macrumors P6
Feb 20, 2009
I wouldn't do this.
SD cards are slow and may not be as reliable as would be a USB hard drive (either HDD or SSD).

512gb SSDs have come way WAY down in price.
Something like a Sandisk Extreme or Samsung t5 will do a beautiful job as a cloned backup drive.

If you ever get into an "I can't boot!" moment (I had one just yesterday with my MacBook Pro), having that bootable cloned SSD will make "getting up and running" again a snap, a 2-minute job (or less).