What is physical memory

Physical memory is relative to virtual memory; physical memory refers to the memory space obtained through physical memory sticks, while virtual memory refers to dividing an area of ​​the hard disk as memory. Common physical memory specifications include 256M, 512M, 1G, 2G, etc.; when physical memory is insufficient, virtual memory can be used instead.

The operating environment of this tutorial: Windows 7 system, Dell G3 computer.

Physical memory (Physical memory) is relative to virtual memory. Physical memory refers to the memory space obtained through physical memory sticks, while virtual memory refers to dividing an area of ​​the hard disk as memory. The main function of memory is to provide temporary storage for the operating system and various programs while the computer is running. Common physical memory specifications include 256M, 512M, 1G, 2G, etc. Nowadays, with the development of computer hardware, 4G, 8G or even higher capacity memory specifications have appeared. When physical memory is insufficient, virtual memory can be used instead. In application, it is, as the name implies, physically, the actual capacity of the memory stick inserted into the memory slot of the motherboard. When looking at the computer configuration, the main thing to look at is the physical memory.

Physical memory is one of the most important resources on the computer. Windows' memory manager is responsible for allocating memory to active processes, device drivers, and the operating system itself. Because most systems can access far more data and code than physical memory, physical memory is essentially the window in which code and data run. So memory capacity has an impact on performance because if the code or data required by the process or operating system does not exist, the memory manager needs to read it from disk.

Description in CPU

Physical memory, the size of the memory space that the CPU's address line can directly address. For example, the 8086 has only 20 address lines, so its addressing space is 1MB. Let's just say that the 8086 can support 1MB of physical memory. Even if we install a 128M memory stick on the board, we can only say that the 8086 has 1MB of physical memory space. In the same way, 32-bit 386 or above CPU can support a maximum of 4GB of physical memory space.

The difference between virtual memory and physical memory: Virtual memory is the opposite of physical memory. It refers to the memory space that is virtually allocated from the hard disk according to system needs. It is a computer system memory management technology and belongs to a computer program. Physical memory is hardware. Because sometimes when you are processing a large program, the system memory is not enough. At this time, the hard disk is used as memory to exchange data and make a cache area. However, the processing speed of physical memory is more than 30 times that of virtual memory.

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