Can a SDXC memory chip serve as a start up disk?

Hello bobfromnm,

Thanks for using Apple Support Communities.

Yes, you may use an SD or SDXC card as a startup disk as long as you have formatted it at Mac OS Extended and changed the default partition table to GUID.

About the SD and SDXC card slot

http://support.apple.com/kb/HT3553

Take care,

Alex H.

Hi Bob,

No worries, I'm happy to help.

Take care,

Alex H.

NOTE: The SD card slot is not fast, but it does may a good emergency boot/recovery device.