According to Linux manual page "time.7" a new timer capability was introduced in kernel 2.6.21. It is called "High-Resolution Timers." According to various other documentation, this new kernel timer capability is now separated from the older, more familiar timers that merely approximate a timeout condition. There are several names encountered trying to learn the mechanism of this clock. Some info can be obtained by entering the /proc/ directory and typing "cat timer_list" in a terminal window. My opensuse 12.3 32 bit desktop kernel indicates "CONFIG_HIGH_RES_TIMERS" is set yes, on some old Intel Core Duo motherboards. I think 64 bit is default set yes. So this is not obscure, off the wall. I think the new feature is intended for multimedia use, in general. But Real Time microsecond accuracy on Linux certainly creates opportunity beyond sound and video. My interest followed playing with XForms-toolkit stripchart demos. Various usual timeout, timer, sleep tools just can't produce a valid sine wave. especially with an active mouse. Obviously, I wasn't alone seeking a specialized precision timer. Learning how to actually use this new Linux feature is currently unclear.