Whether BBB can support boot from a 16G micro-SD

Now I'm ready to build a demo system which is Zigbee Lighting Gateway, the url is:http://processors.wiki.ti.com/index.php/ZigBee_Lighting_Gateway.

In this website, there mentioned information below:

Create a Bootable SD card for the BeagleBone

1. Use 7-Zip to Extract the .img file from the Ninja-Factory-.gzRecovery-20-12-2013.img file just downloaded.
2. Use Image Writer to copy the .img file onto the micro-SD card (8GB Micro-SD card - 7.726GB minimum).

I have a 8G micro-SD,but when pluged in to PC, there's only 7.4G and this is smaller than the 7,726GB. So my problem is that if I got a 16GB micro-SD,and copy the .img into it, the BBB can Load this Image into emmc from 16GB but not 8GB micro-SD.