SD Card vs USB3 Thumb Drive vs USB3 External Hard Drive


macrumors member
Original poster
Aug 10, 2009
Hi guys,

I'm going to be doing some video editing on my MacBook Air (top of the line, definitely not ideal machine for this, but much better than the last time I did this stuff 8 years ago on a G5). I'm going to need to keep the video files on an external drive of some sort. What would be faster:
SD Card
USB3 Thumb Drive
USB3 External Hard Drive

Of course I know Thunderbolt would be the best, but I'm looking for something less expensive. I already have a bunch of USB2 hard drives lying around so I could just buy a USB3 enclosure and pop one in. The SD Card would be the most elegant, but is it fast enough?

Thanks in advance!


macrumors 68030
Feb 10, 2008
How much storage space do you need?

SD cards come in a wide variety of speeds. The fastest ones with any capacity (64+GB) are costly. The MacAir uses the USB bus to talk to the SD card I think (slows things down). Thumb drives are unreliable for large file saving, like video. They overheat and slow down.

A USB drive is your best bet. But unless you go with a two drive RAID or SSD, you won't notice much difference between USB2 and USB3 as the limit is the drive. New 1TB USB3 drives are less than $100 now days, which hardly makes it worth picking up a $30 enclosure and putting one of your old drives in it.

I recently picked up a Samsung 840 series SSD in 128GB for $115 and a StartTech USB enclosure (supports UASP) for $24. That is a fast, reliable, and durable drive for $140 total. SSDs have come down in price recently, and you can get 240GB for less than $100 in consumer grade.

Does your Air support USB3? Older ones don't.

Don't forget a backup plan.
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macrumors 6502a
Dec 22, 2008
SD Card speeds can be fast (in the 80MB/s range for read and 60MB/s write) but can also be very unreliable (same card can go down to 1MB/s for small writes. Example:

USB 3 pen drives, if fast, can be very fast (in the 200MB/s range for large reads) but also very slow for small transfers. See

USB 3 HDs seem to range in the SD Card speed range. With mostly the same characteristics: fast with large transfers, slow with small transfers. They are more reliable in terms of durability but more fragile if dropped while in operation.

If you want awesome speed, durability and no fear of data loss in case of dropping your disk, you can also consider a third option: an SSD disk (Like Crucial M4 or Samsung Evo) in a SATAIII USB 3 enclosure (like: Which will give you VERY fast speeds with the correct case+SSD combo (sub-500MB/s read/write with large files and ~15MB/s on small transfers).


macrumors member
Original poster
Aug 10, 2009
Thanks for the replies guys. I have a '13 Air, so it does support USB3 and I will need at least 64 GB I think. I will be editing with iMove and it appears according to this article:
that it has to be used with an external hard drive, not an SD card. "Note: To use an external hard disk with iMovie, it must be formatted as Mac OS Extended (Journaled). iMovie doesn’t support network-attached storage or external flash memory drives."

I guess what both of you are saying is that my best bet is SSD + USB3 Enclosure. Okay, I think that can be done for a reasonable price. I did see this traditional spinning disk really cheap on Amazon, but probably not worth it:

Thanks for the replies.