Disk belongs to external memory, so what is the difference between the storage principle of external

External memory refers to storage other than computer memory and CPU cache, which can still store data after power failure, and hard disk is one of the external storage. The most prominent feature of internal memory is that the access speed is fast, but the capacity is small and expensive; External memory is characterized by large capacity and low capacity, but slow access speed. Internal memory is used to store programs and data that are immediately needed; External memory is used to store programs and data that are not in use for the time being.

There is often a frequent exchange of information between the inner and outer memory. External memory is usually magnetic media or optical discs, such as hard disks, floppy disks, tapes, CDs, etc., which can store information for a long time and does not rely on electricity to store information, but the speed is much slower compared to CPU cache or memory.

Memory is constantly refreshed, such as the CPU cache, and your memory module.

You can think of it as a potential state.

A high potential means 1 and a low potential means 0

So once the power is out.

It doesn't mean anything.

Because of this, it can be read directly without conversion. So it's fast, but the capacity doesn't increase easily. It cannot be persistently stored.

External memory refers to disks, tapes, optical discs, USB flash drives, and so on. They all rely on magnetism, optical pits, and storable semiconductors, which can be stored in media that do not need to be powered on to hold, so they can store data permanently, but when they read data, they need to do it.

Photoelectric conversion, or magnetoelectric conversion, requires a conversion process, so the speed is relatively slow compared to memory. The capacity can be made relatively large according to the characteristics of the medium, and the data can be stored permanently.

Computer disk refers to your computer's hard disk, regardless of memory or external memory. If you have to say that the whole new word comes out, then you can understand that the computer hard disk is a memory disk, and you can understand the USB flash drive, mobile phone, tablet and other devices used for mobile storage as an external disk. There is no distinction between inside and outside for a single computer.

I'm the Murokai Fengzi.

Memory is designed to increase access speed.

The data in the memory disappears when the power goes down, but the hard drive does not.

Memory. It is used as a cache, first read out the data from the hard disk and put it in memory, so that the CPU is fast when it is called.! ～

So. The read and write speed of the memory is much faster than that of the hard disk! ～

Compared to external memory,Internal memoryIt is characterized by the extremely fast storage speed of internal memory, but the storage capacity is relatively small.

The internal memory stores information very quickly, but the storage capacity is relatively small. Internal memory refers to RAM, memory, extremely fast read and write speeds, small capacity, and information loss after power failure. External memory is characterized by large capacity and low capacity, but slow access speed.

External memory is also an input and output device, which can only exchange information with internal memory and cannot be directly accessed by other parts of the computer system.

External memory includes floppy disks.

Hard disks, optical discs, etc., and the corresponding drives are also called external memory, and some memories and storage media are made together, such as hard disks and U disks. Wait a minute.

Computer memory is divided into internal memory.

and external memory:

Memory is further divided into random access memory.

RAM) and read-only memory.

ROM) two. ROM can only read out information, can not write information, the storage information here can be stored for a long time without being affected by power outages, and the information can be read out from it after turning it off. Therefore, the ROM often stores the monitoring program and some service programs that manage the machine itself.

RAM is readable and writable, but the information inside automatically disappears after the shutdown. Therefore, it is generally used to store the programs required for the computer to run, which we usually call memory modules.

This refers to RAM.

External memory is an important part of storing information in a computer, which is used to store a large amount of data, such as hard disks and floppy disks.

CD-ROMs, USB flash drives, portable hard disks.

Wait a minute. Among them, the hard disk is fixed in the main computer case, and the capacity ranges from tens of gigabytes to hundreds of gigabytes.

Compared with external memory, memory has the characteristics of fast access speed. Memory is one of the most important components of a computer, and it is the bridge between external memory and CPU. The running of all programs in the computer is carried out in memory, so the performance of the memory has a great impact on the computer.

Memory, also known as internal memory and main memory, is used to temporarily store computing data in the CPU and to exchange data with external memory such as hard disks. As long as the computer is running, the operating system will transfer the data that needs to be calculated from the memory to the CPU for calculation, and when the operation is completed, the CPU will send the result out, and the operation of the memory also determines the stable operation of the computer. The memory module is composed of parts such as the memory core blind patch, circuit board, and gold finger.

The main memory of Lu Hui to structure.

Memory generally uses semiconductor memory cells, including random access memory (RAM), read-only memory (ROM), and cache. Simply because RAM is the most important memory of them all. (Synchronous) SDRAM Synchronous Dynamic Random Access Memory:

The SDRAM is 168 pins, which is the memory currently used by Pentium models and above. SDRAM locks the CPU and RAM together through the same clock, enabling the CPU and RAM to share a clock cycle, work synchronously at the same speed, and the rising edge of each clock pulse starts to pass data at a speed that is 50% faster than EDO memory.

1. The internal memory is used to store those programs and data that need to be used immediately; The external memory is used to store programs and data that are not used for the time being. There is often a frequent exchange of information between the inner and outer memory.

2. Refers to different external memory: external memory refers to storage other than computer memory and CPU cache, which can still save data after power failure.

3. Different nature: As long as the computer starts running, the operating system will transfer the data that needs to be calculated from the memory to the CPU for calculation. When the operation is completed, the CPU will transmit the result.

External memory refers to storage other than computer memory and CPU cache.

4. Composed of different internal memory: composed of memory chips, circuit boards, gold fingers and other parts. External Memory:

Magnetic core (used both as memory and external memory because data is not lost), magnetic tape (still used for large-scale data backup of poor spikes), disk (including soft disks, hard disks).

Hard disks are external memory. The differences are as follows:

First, the reference is different.

1. External memory: External memory refers to the memory of Luxun in addition to the computer memory and CPU cache of Huihan, which can still save data after power failure.

2. Memory: also known as internal memory and main memory, its function is to temporarily store the computing data in the CPU, as well as the data exchanged with external memory such as hard disks.

Second, the characteristics are different.

1. External memory: It is characterized by large capacity and low capacity, but the access speed is slow.

2. Memory: It is characterized by fast access speed, but small capacity and high price.

Third, the use is different.

1. External memory: used to store those programs and data that need to be used immediately.

2. Memory: used to store programs and data that are not used temporarily.

The internal memory of the computer memory is divided into temporary data when it is turned on, and there is no time to shut it down. Generally refers to memory modules.

The external memory is turned on and off in the machine, and it will not be lost. Generally, it refers to hard disks, tapes, disks, etc.

ROM stands for Read-Only Memory, which is a type of solid-state semiconductor memory that can only read out previously stored data. It is characterized by the fact that once the information is stored, it cannot be changed or deleted. It is usually used in electronic or computer systems that do not require frequent data changes, and the data does not disappear due to power off.

RAM (Random Access Memory) RAM -Random Access Memory. Storage is storage that can be removed or stored as needed, and the speed of access is independent of the location of the storage cell. This storage pecha will lose its storage content when the power is lost, so it is mainly used to store programs that are used for a short period of time.

According to the different information stored, random access memory is divided into static RAM (SRAM) and dynamic random access memory (DRAM).

Hard disks are external storage.

Hard disk drive (HDD) is a non-volatile storage device based on a hard rotating platter on a computer, which stores and retrieves digital data on a flat magnetic surface, and the information is written to the disk by the electromagnetic current through the magnetic head very close to the magnetic surface, and the electromagnetic current changes the polarity by the electromagnetic current, and the information can be read in the opposite way, for example, when the reading head passes over the top of the recorded data, the magnetic field causes the electrical signal in the coil to change. The hard disk reads and writes by random access, so the data in the hard disk can be read in any order [2].

A hard disk consists of one or several disks that rotate at high speed and a head that is placed on the actuator cantilever.

Early hard disk storage media were replaceable, but today's typical hard drives use a fixed storage medium with the disc and head encapsulated in the body (except for a filtered air hole to balance out the air pressure difference caused by the heat generated during operation).

Hard disks were introduced by IBM in 1956[3] and became the main secondary storage device in general-purpose computers in the early 1960s, and with the advancement of technology, hard disks have also become the main components of servers and personal computers.

HDDs are broadly divided into ATA (IDE) and SATA as well as SCSI and SAS according to different data interfaces. The interface speed is not the actual hard disk data transfer speed, and the actual data transfer speed of the hard disk that is not based on flash memory technology generally does not exceed 300MB s.

Hard drive manufacturer.

Western Digital

IBM: The hard disk division was acquired by Hitachi in 2003.

Hitachi Global Storage Technologies: Acquired by Western Digital in 2011.

Seagate

Quantum: The hard disk division was acquired by Maxtor in 2000.

Conner: Acquired by Seagate in 1996.

Maxtor: Acquired by Seagate in 2006.

Samsung Electronics: The hard disk drive business was acquired by Seagate in 2013.

Toshiba (toshiba).

Fujitsu: On February 18, 2009, the hard disk division was acquired by Toshiba.

Excelstor

7 in the computer accessories diagram is the location of the hard disk.