A MBps and MB/s refer to megabytes per second which are units of data transfer speed.Data transfer speeds measure how quickly data can be moved between different locations. Megabytes per second are often confused with megabits per second which are abbreviated by Mb/s or Mbps, the lower case b stands for bit. A megabyte is eight times larger than a megabit so a megabyte per second is eight times faster than a megabit per second. Network device speeds are generally discussed in terms of megabits but for storage devices megabytes are the more common unit. In order to work out read/write speed in MBps a file is read/written to a device. Dividing the size of the file in megabytes by the time taken in seconds gives the MBps read/write speed. For example if it takes 10 seconds to write a 100 megabyte file, the transfer speed is 10 MBps. There are lots of free benchmarking programs specifically designed to measure transfer speed. Some of the most popular and oldest disk benchmarks are Crystalmark, Atto and the more recent UBM. These utilities provide a safe and easy way to benchmark flash drives, regular hard disks and solid state drives.