I'm considering getting a SDXC card to extend the drive space of my Macbook Air. I just want to make sure both the 64 GB and 128 GB SDXC cards work on the 2011 Macbook Air.
It appears to work according to several reports:
There has been some concern that Apple lists the MacBook Pro models on its web site as having an SDXC card slot, for high-capacity SD cards, and only lists the card reader on the Air as an SD card one. We tried a 64GB SanDisk SDXC card in the MacBook Air's card reader, and the system recognised it as the appropriate size and was able to access files on it. However, if you're looking to get a massive SD card in order to augment the smallish 128GB SSD built into the Air, note that the card slot leaves the SD card hanging halfway out on the side of the system, so it's not appropriate for full-time use.
I got my Transcend SDXC 64GB flash card, and yes, it reads and writes perfectly in my MacBook Air.
According to this discussion thread on Apple's forums, both 64 and 128 GB SDXC cards are well supported on the latest [mid-2011 at the time of writing] MBA, provided you format them using the Mac OS X Journaled option.
My mid-2011 MacBook Air recognizes and uses a Komputerbay 64 GB SDXC card just fine. It's a $54 card from Amazon. However, I only get read speeds around 33 MB/s from this card.
the card reader is on a USB 2 bus so it will never be all that fast. As some point they put the card reader on a ?pci-e? bus and it has higher possible speed.