Speeds vary by capacity. [256GB-1TB]: Up to 200MB/s read speeds, engineered with proprietary technology to reach speeds beyond UHS-I 104MB/s, require compatible devices capable of reaching such speeds. Write speed up to 140MB/s. Based on internal testing; performance may be lower depending upon host device, interface, usage conditions and other factors. 1MB=1,000,000 bytes. [64GB-128GB]: Up to 200MB/s read speed, engineered with proprietary technology to reach speeds beyond UHS-I 104MB/s, require compatible devices capable of reaching such speeds. Write speed up to 90MB/s. Based on internal testing; performance may be lower depending upon host device. 1MB=1,000,000 bytes. [32GB]: Up to 100MB/s read speed. Write speed up to 90MB/s. Based on internal testing; performance may be lower depending upon host device.