The Time Stamp Counter (TSC) is a 64-bit register present on all x86 processors since the Pentium. It counts the number of cycles since reset. The instruction RDTSC returns the TSC in EDX:EAX. In x86-64 mode, RDTSC also clears the higher 32 bits of RAX. Its opcode is 0F 31. Pentium competitors such as the Cyrix 6x86 did not always have a TSC and may consider RDTSC an illegal instruction. Cyrix included a Time Stamp Counter in their MII.
Read more about Time Stamp Counter: Use, Implementation in Various Processors, Operating System Support, Other Architectures
Famous quotes containing the words time, stamp and/or counter:
“When people ask for time, it’s always for time to say no. Yes has one more letter in it, but it doesn’t take half as long to say.”
—Edith Wharton (1862–1937)
“Each victim of suicide gives his act a personal stamp which expresses his temperament, the special conditions in which he is involved, and which, consequently, cannot be explained by the social and general causes of the phenomenon.”
—Emile Durkheim (1858–1917)
“The technological landscape of the present day has enfranchised its own electorates—the inhabitants of marketing zones in the consumer goods society, television audiences and news magazine readerships... vote with money at the cash counter rather than with the ballot paper at the polling booth.”
—J.G. (James Graham)