sdd is a replacement for a program called 'dd'. sdd is much faster than dd in cases where input block size (ibs) is not equal to the output block size (obs). Statistics are more easily understood than those from 'dd'. Timing available, -time option will print transfer speed Timing & Statistics available at any time with SIGQUIT (^\) Can seek on input and output Fast null input Fast null output. Support for the RMT (Remote Tape Server) protocol makes remote I/O fast and easy.
sdb is a really simple program to benchmark disks. It only writes/reads data sequentially to/from a file and calculates the performance of this action. A memory buffer is used for input/output to get values close to the real performance of the disk or RAID system. You can use flags like O_DIRECT and O_SYNC to avoid buffering by the operating system. It is similar to dd, but there are some differences, since dd was not created for benchmarking a disk. It is possible to initialize the buffer with random values before writing them to the disk or a file on the disk. It is a simple but effective program to get the maximum speed of a disk. Due to the simplicity, you will get the results much faster than with a more complex benchmark.
tstime is a command that is similar to the time(1) command, but in addition to the runtime, it also prints the highwater memory usage (RSS+VMEM) of the controlled process. tsmon is a command that prints the runtime/highwater memory usage of every process that exits on the system until the tsmon is quit. These programs use the taskstats delay accounting interface of the Linux 2.6 kernel.