Intel processor structure-multi-core programming study Note 1

Single-core processor

Computer system diagram:

The previous chipset consists of two chips, called nanqiao and beiqiao, which are connected through PCI. Later, Intel replaced beiqiao with MCH (memory controller hub) and ICH (I/O controller hub) with nanqiao. The two were connected using DMI (direct media interface. In addition, the master processor is connected to the chipset through the FSB (front side bus.

A diagram of the processor's functional modules and the basic execution steps of commands within the processor:

Based on different processor cores, Intel processor can be divided into two basic types:

L excessive processor.

L display the Parallel Instruction Computing Architecture (explicitlyparallel Instruction Computing, epic) processor.

The Intel Pentium processor uses an over-standard structure, and the intel itanium processor (for enterprise servers) uses an epic structure.

The two processors have their own advantages and disadvantages. For details, see chapter 9th of multi-core programming technology.

Is the internal execution flowchart of the Intel Pentium 4 processor:

The following figure shows the execution process comparison between an over-standard processor and an epic processor:

It can be seen that, although it is a single-core processor, no matter which structure, the command execution can be parallel.

Multi-core processor

A single-core processor cannot implement multi-threaded parallel processing without using hyper-Threading Technology. Although you can write multi-threaded programs when writing programs, this multi-threaded concurrent execution only feels like that at some point in time, there is actually only one thread to execute on the hardware.

Hyper-Threading Technology is a hardware mechanism that supports simultaneous execution of multiple hardware threads within a single clock cycle.

Comparison between single-core processors that do not support hyper-threading and multi-core processors that support hyper-threading:

It can be seen that the hyperthreading technology processor is divided into two logical processors, called the logical processor, because physically it corresponds to the same processor. When two threads run simultaneously, hyper-Threading Technology will strictly interlace the commands of the two threads into the execution pipeline. Since the two hardware threads are working in the processor at the same time, they can be executed concurrently. However, because the two hardware threads share a large amount of physical resources, sometimes there is a conflict of use, which limits the concurrency.

Different from hyper-threading technology, multi-core technology means that the processor has multiple execution cores physically.

The comparison between single-core and various multi-core processors is shown below:

Multi-core processors can also support hyper-threading technology, such:

References:

Multi-core Programming Technology