The Kingston UHS-I U3 64GB SDXC card can provide extremely fast transfer rates when used in the proper device. Testing confirmed that you can indeed achieve the rated read speed of 90MB/s and the rated write speed of 80MB/s, which are both very impressive values for an SDXC/SDHC card. Keep in mind that you will not see these speeds with a camera or card reader that is not UHS-I capable.