What is the ability of a multicore processor to execute two or more instruction streams simultaneously called?

• A. Hyperthreading
• B. Pipelining
• C. Multithreading
• D. Superscalar

Answer: (A)

Simultaneous hardware threads running on a single core is what hyperthreading enables. This is Intel’s name for simultaneous multithreading, where each core can manage two (or more) threads at the same time. By keeping two instruction streams in flight, the processor can hide stalls—like waiting on memory or a slow cache lookup—by switching to the other thread, so the core’s execution units stay busier and overall throughput improves.

This is different from pipelining, which overlaps stages of a single instruction stream, and from superscalar, which increases how many instructions from one thread can be issued per cycle. Multithreading is the broader idea of running multiple threads; hyperthreading is the specific hardware approach that makes concurrent execution of multiple streams on a core possible.