Single-core processors:
a single CPU, and the chip is relatively large.
Multiprocessor systems:
there are a motherboard on two or more CPU chips, different CPU by a system bus to complete the communication.
Communication efficiency is low, we can not take advantage of the computing power of each CPU is provided.
Poor scalability, you want more processing power, need a motherboard with more processors.
Hyper-Threading Technology appears:
the same CPU chip copy some internal components, such as a register or a buffer, to share information between two different threads of execution, rather than through the bus, to speed up the calculation process.
A chip, by the process of switching to achieve parallel processing. From the operating system point of view, like having two CPU at work.
Note: not produce a physical core 2 times the processing power. It is impossible to provide a complete parallel processing capabilities.
Multi-core processor architecture
miniaturization of all components of the processor, called a physical core. A plurality of physical core encapsulated in a chip, to form a multi-core architecture.
Each physical communication between the core through an internal bus, without going through a system bus. Between each of the core is relatively independent of the physical, it can be completely parallel processing capabilities.
Performance: 1 dual-core CPU> single-core CPU. 1 Hyper-Threading> 2 non-single-core CPU Hyper-Threading