If the motherboard does not support USB 3.0, then you will be limited to whatever it DOES support.
However - according to ASUS: http://www.asus.com/Motherboards/M5A97/
USB 3.0 support
Experience ultra-fast data transfers at 4.8 Gb/s with USB 3.0–the latest connectivity standard. Built to connect easily with next-generation components and peripherals, USB 3.0 transfers data 10X faster and is also backward compatible with USB 2.0 components