I recently the product, but here are the results of my tests: 64GB USB3.0 version tested on a motherboard ASUS H87I-PLUS (Intel USB controller) with Windows 8.1 x64: Large files (2x15Go) from and on a Western Digital Black 1TB HDD (SATA 6Gbps internal) Copy HDD to the key (write)> 105 MB / s average. Copying to the HDD key (read)> 115 MB / s average. Excellent, guaranteed 5 years, all less than 30 euros, what more !! Merki Amazon ^^