Complex sentence: In the late 1990s, the idea of executing instructions from multiple threads simultaneously, known as simultaneous multithreading, has reached desktops with Intel's Pentium 4 processor, under the name hyper threading.
Split into simpler sentences: In the late 1990s, the idea of executing instructions from multiple threads simultaneously has become known as simultaneous multithreading. This feature was introduced in Intel's Pentium 4 processor, with the name hyper threading.