Virtual memory, physical memory /ram what

Original article , Reprint please indicate the source .

Preface

Understand a few concepts before understanding
1>RAM Ram = Physical memory ： This is a piece of hardware inserted into the computer mainframe . That is what we often call memory module , There are also called running memory .
give an example ： My colleague told me , His computer memory 8 individual G, Want to play and eat chicken . I answer him ： You didn't 8 individual G, Can't play , Add one 8G Memory module .

2> Virtual memory ： disk space , The system can be managed by default , We can also participate in setting its size and which drive letter to use . This document is called FilePage.SYS. It's easier to use than RAM slow ： The speed of physical memory usage is that of virtual memory 30 More than times .

The difference between virtual memory and physical memory ： Virtual memory is the opposite of physical memory , It refers to the memory space allocated from the virtual address of the hard disk according to the needs of the system , Is a computer system memory management technology , It belongs to computer program , Physical memory is hardware . Because sometimes when you deal with large programs, the system memory is not enough , At this time, the hard disk will be used as memory , To exchange data as a buffer , However, the processing speed of physical memory is that of virtual memory 30 More than times .

Virtual memory

First, virtual memory is the memory space on the hard disk .
When the space on our memory module cannot be allocated , It is also said on the Internet that the memory allocation of the memory module is slow , At this time, we will use our virtual memory . That is, I can use memory module space + Use disk space together . however
We can participate in specifying the size of this virtual memory ： Generally, the system will be managed as a system disk by default , You can also set other drive letters . However, it should be noted that the disk used by your virtual memory must have a large amount of remaining space , You said it used C disc , result C The plate is left 1G There's space , At this time, running a larger game will report that the memory cannot be allocated . For example, the error report of the following pictures .

reflection ： So when our computer RAM That is, when our memory module is large enough , Do you still need virtual memory ？
Then someone asked , How big is it big enough . We assume that When you reach 32G,64G.
answer ： I don't think it's necessary , Your memory is big enough , Why use disk memory ？ Disk memory is inherently larger than RAM Reading is much slower . There are fast and good , Why not . Right .

It can be understood that virtual memory is a backup force when the memory of our memory module is insufficient .

Physical memory /RAM

It also introduces , This is our memory module .

   A running process , The memory he needs may be greater than the sum of the memory modules , For example, your memory module is 256M,
   Your program has to create one 2G Data area of , Then not all data can be loaded into memory together （ Physical memory ） in ,
   There must be some data to be put into other media （ For example, hard disk ）, When the process needs to access that part of the data , Enter physical memory through scheduling .
   therefore , Virtual memory is the sum of all memory space when a process is running , And some of them may not be in physical memory ,
   Physical memory is the memory module we usually know . Some places , This virtual memory is also called memory swap area .

thank you , It's not easy to create , Great Xia, please stay … Move your lovely hands , Give me a compliment before you go <(￣︶￣)>