What is Intel Hyper-threading? What are the Uses of Hyper-threading?

Hyper-Threading

Hyper-Threading is Intel’s proprietary simultaneous multithreading (SMT) technology, which is used to convert each physical core of the processor into two virtual cores in order to improve the performance of that processor. So, a Quad-core Intel CPU that supports Hyper-threading will act like an Octa-core CPU.

Understanding Hyper-Threading with example:

Four Scenarios with and without Hyper-Threading:

  1. Case 1: Dual-Core CPU, without Hyper-Threading = 2 Logical Processors
  2. Case 2: Dual-Core CPU, with Hyper-Threading = 4 Logical Processors
  3. Case 3: Quad-Core CPU, without Hyper-Threading = 4 Logical Processors
  4. Case 4: Quad-Core CPU, with Hyper-Threading = 8 Logical Processors

Performance Impact:

  • Case 4 is the fastest. Because it has the most number of logical processors.
  • Case 1 is the slowest. Because it has the least number of logical processors.
  • Case 3 is faster than Case 2. In both of the cases, the total number of logical processors are 4. But the total number of logical processors in Case 4 are equal to the total number of physical cores of the processor; whereas in Case 2, only 2 out of 4 logical processors are real or physical, and the other 2 are virtual, which do not provide the same level of performance as the real physical processors.

Hyper-threading lets you bring more performance out of you processor.