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That drive states to have 45 MB/s write and 20 MB/s read speeds. USB 2.0 offers up to 37 MB/s read and write speeds, but with most cheap USB flash memory drives, the flash memory is the cheap part and does not offer more than 20 MB/s write or read speeds, often only 5 to 10 MB/s.

As for a good USB 3.0 flash memory drive, it should at least offer 50 to 100 MB/s read AND write speeds to take advantage of the USB 3.0 connection on your MacBook Air. But then again, those might be quite expensive, more expensive than small 2.5" S-ATA HDDs in a USB 3.0 enclosure offering 75+ MB/s write and read speeds, if all you do is transfer data between iMac and MacBook Air.
 
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I got the Sandisk Extreme 64gb usb 3.0 and it gets like 180 read/write speeds...basically the fastest 3.0 flash drive around. But it will cost more than others...$100 online or $140 at Staples.
 
I got the Sandisk Extreme 64gb usb 3.0 and it gets like 180 read/write speeds...basically the fastest 3.0 flash drive around. But it will cost more than others...$100 online or $140 at Staples.

Thanks! I am scrapping the scan disk.
 
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