I took 252+ digital photos this AM (493 MB = apx 2 MB ea) & updoaded them from the SanDisk card to the PC using a SIIG USB 3.0 card reader.
In Win7 x86 it took: 15.7 sec = 31.4 MB/s
In Win8 PRO x86 it took: 14.5 sec = 34 MB/s
As stated above the -
Win7 install used the ASUS chipset/USB 3.0 driver
Win8 install uses the Miocrosoft Win8 USB 3.0 driver.
I don't know if its the driver or the OS for faster in Win8 results though.