The significance of bandwidth in a computer system

The frequency range of the energy concentration of the signal. As for the percentage of the range of signal energy concentration that is considered bandwidth, it depends on different actual needs. The criterion for judging is that the signal spectrum in a certain frequency range has basically provided the information we need, then the signal spectrum outside this frequency range becomes dispensable.

This frequency range is the bandwidth. To understand it deeply, you need to understand the concept of signal spectrum. With the concept of signal spectrum, the problem becomes clear.

The bandwidth of the transmission line. The bandwidth of the transmission line and the bandwidth of the signal are different. As a channel, the transmission line is seen as a system. It suppresses the spectrum of the signal that is fed into it, which can also be called filtering.

Different frequencies have different suppression characteristics, and the system function or frequency response function is the characterization of this system characteristic.

Generally speaking, we stipulate that the channel suppresses the power of the input signal of all frequencies to half of the signal power in the passband, that is, it drops by 3db, that is, when it reaches the so-called half-power point, the frequency range corresponding to the half-power point on the left and right sides of the passband is the channel bandwidth.

The speed at which a computer uploads data is also known as the uplink bandwidth of the networkNetwork speed abbreviationSpeed.

Dial-up Internet accessThe broadband speed is 512k, 1m, etcWi-FiThe network speed is generally 11m or 55m.

1. Computer LAN.

It consists of a network workstation, a network server, a network printer, and a network interface card.

network card), transmission medium and network interconnection equipment.

2. Classification of computer LAN. According to the transmission regeneration medium used, it is divided into wired network and wireless network; By the topology of the interconnection of various devices in the network.

It is divided into bus type, star network, ring network, tree network and network type; According to the access control method used by the transmission medium, it is divided into Ethernet.

Mark ring networks, FDDI networks, switched LANs, etc.

3. Ethernet is the most commonly used kind of local area network, which adopts a bus structure, and all nodes are connected to a bus through an Ethernet card. The bus cable it uses is coaxial.

4. The LAN service is connected to the computer on the LAN, and it must be logged in to access the network to access the resources on the network. The services provided by the LAN usually include: file services, also known as shared storage services.

When a user logs on to the network, the server's hard disk and optical drive are mapped to the storage devices on the workstation.

Users can access programs and data in it just as they would with a local disk. Print service, message service, application service.

5. There are two commonly used working modes in the local area of the LAN software PC: peer-to-peer mode and client server (CScapper) mode. In peer-to-peer mode, each PC in the network can be used as both a workstation and a server; The client-server pattern is where every computer in the network plays a fixed role.

It's either a server, a sharp, or a client.

The concept of bandwidth: Bandwidth refers to the amount of data that a communication channel (such as network, cable, optical fiber, etc.) can transmit per unit of time. It is usually expressed in terms of bit rate (bit s) or byte rate (byte s).

The larger the bandwidth, the more data can be transmitted per unit of time, so the higher the data transmission speed. In network communication, bandwidth usually refers to the network transmission rate, that is, the ability of the network to transmit data. For example, a network bandwidth of 1Gbps means that the network can transmit 1Gbps of data in one second.

The role of bandwidth: Bandwidth is a measure of the network transmission rate, which determines how much data a network can transmit per unit of time. The role of bandwidth is as follows:

1.Network transmission speed: Bandwidth determines how much data the network can transmit per unit of time, so it directly affects the network transmission speed.

2.Network quality: The higher the network bandwidth, the faster the network transmission speed and the better the network quality.

4.Network traffic control: Bandwidth can be used to control network traffic, such as throttling the bandwidth of a user or application to ensure that network usage by other users or applications is not affected.

5.Network planning and optimization: Understanding network bandwidth usage can help network administrators plan and optimize their networks to improve network performance and efficiency.

Bandwidth refers to the total amount of data that can be transmitted in a unit of time, and it is equal to the product of the bit width and the operating frequency. It reflects the ability of the communication line to transmit data. For example, for a 64-bit, 800MHz FSB, its bandwidth is equal to 64bit 800MHz 8=; The bandwidth of the 32-bit, 33MHz PCI bus is 32bit 33MHz 8=133MB s.

Total amount of information: q = 64 bits 4 = 256 bits of sequential memory and cross memory read out 4 words respectively:

t2 = m t = 4×200ns =8×10 –7 (s)t1 = t + m – 1)τ = 200 + 3×50 = ×10 –7 (s)

The sequential memory bandwidth is:

w1 = q t2 = 32 107 (bit s) The cross-memory bandwidth is:

w2 = q t1 = 73 107 (bit s).

In basic electronics and electronic communications, broadband describes a continuation number or an electronic line that contains or is capable of simultaneously handling a wide range of frequencies. Broadband is a relative way of describing it, and the larger the frequency range, that is, the higher the bandwidth, the more data can be transmitted.

In computer systems, bandwidth is used as one of the indicators to identify bus and memory performance.

Bus bandwidth refers to the total amount of data that a bus can transmit per unit of time, equal to the product of the bus bit width and the operating frequency. For example, for a 64-bit, 800MHz FSB, its data transfer rate is equal to 64-bit 800MHz 8(byte)=

Memory bandwidth refers to the data transfer capacity that a memory bus can provide. For example, if the data transmission frequency of DDR400 memory is 400MHz, then a single module has a bandwidth of 64bit 400MHz 8(byte)=.

Bandwidth: The width of the frequency band occupied by the signal.

It's two non-stop concepts. Bandwidth is the ability of a channel to transmit information; The transfer rate is the amount of information transmitted in a channel per unit of time.

Bandwidth indicates the width of the frequency band.

In computer network applications, the bandwidth of a signal refers to the frequency range occupied by the various different frequency components contained in the signal; Bandwidth also indicates the ability of a communication line to transmit data, i.e., the "maximum data rate" that can be passed from one point in the network to another in a unit of time.

Data transfer rate.

It refers to the binary that is transmitted every second.

The amount of information of a pulse, usually in bits. It is a measure of the number of binary bits transmitted by the line per unit of time, and it is a measure of the ability of the line to transmit information. The frequency of the channel is a measure of the number of oscillations of the electrical signal of the line per unit time, and the relationship between the frequency and the data transmission rate is similar to the relationship between the number of lanes on the highway and the traffic flow.

To put it bluntly, bandwidth is the ability of a channel to transmit information. Rate is the amount of information transmitted in a channel per unit of time.

As I understand it, the transmission rate generally refers to the rated transmission number rate, while the bandwidth refers to the ability of the channel to transmit data, that is, the maximum transmission rate. Therefore, the popular understanding is the difference between the rated rate and the maximum rate.

It can be understood in this way: a highway can be passed by several people at the same time. Everyone walks a few steps per second, and each step walks a few meters.

It is expressed by the formula: transmission rate = number of people passing at the same time x how many steps per person per second x how many meters per step is taken, if the maximum value is taken, it is the maximum transmission rate. Here, the number of people passing at the same time is the bandwidth.

Speed refers to the transmission of data by a computer over a network, and bandwidth refers to the maximum speed at which a network can allow data to be transmitted.

The corresponding objects are different.

The object of the description of the rate is data: the rated rate at which data is transmitted through the network.

Bandwidth is described as the entire channel: how much data can be transmitted per second for the entire channel, which is the maximum data rate for the entire channel.