Why Has My Computer Slowed?

Processing speed is one of the most important performance indicators of computer systems. In general, processing speed refers to the number of floating-point operations per second by the CPU. In today's computers, processing speed has various concepts, which can be analyzed from the perspective of software and hardware. From the perspective of software, processing speed refers to the speed at which the system or application processes user requests. From a hardware perspective, processing speed is primarily related to computer components.

There are multiple concepts of processing speed. From a system perspective, processing speed refers to throughput. Throughput refers to the unit time

Floating point operations per second (peak speed per second) is performed per second

The terminal-level factors that affect system slowness are: virtual memory settings, whether the system driver settings are reasonable, timely deletion of redundant DLL programs in Windows, unreasonable hard disk partitions, insufficient hard disk space, small memory, and unused services are not timely Uninstallation, etc., will cause the system speed at the terminal level to decrease.

There are many impacts on the speed of network information transmission, such as irrational network topology, irrational firewall settings, blocked port bottlenecks, and computer viruses. For example, the enterprise unified more than 40 suppliers to the new industrial park, and at the same time, the sales method has also changed from agency wholesale to franchisees covering all regions. At the same time, new requirements may be put forward for the access requirements of a certain network device. Low performance poses bottlenecks, such as insufficient bandwidth at the aggregation layer switches. Similar problems exist in the reorganization of other business models within the enterprise, and the network topology should be adjusted according to the actual situation. When the network speed slows down, use the network management software to check the data traffic of routers, switches, and server ports, confirm the location of network data flow bottlenecks, and try to increase the bandwidth. There are missing domains, abnormal CPU status, unreasonable operating system settings, slow disk I / O speed, network card I / O bottlenecks, etc., which affect the server running speed, especially the CPU usage. If it is often at 100%, then it is necessary to suspect Is the virus invading the system? Use the optimization master and other tools to stop unused services and clear unused dynamic libraries from memory, which can effectively improve the server's operating speed. For example, the index table is not made, the data table is not properly planned, there are bugs in some program code, and there are too many redundancy problems, including coding specifications. The increase in system access cycles is the reason that affects the speed of the database. When developing systems, people often pay too much attention to whether the system's business functions are correct, and it is easy to ignore the performance differences between different implementation methods. Improper index design, inappropriate data table planning, and insufficient connection conditions all involve databases. Layer resource configuration, network layer flow control, and overall design of the operating system layer, make full use of indexes, reduce I / O times for table scans, and clear program bugs, which can effectively improve database access speed. After the virus invades, it takes up a lot of system memory resources, causing normal programs to run slowly due to lack of main memory. At the same time, virus programs will force the CPU to execute useless junk programs, leaving the system always busy, which affects the operation of normal programs. , Causing the computer to slow down. Systematic hazards to the system. Therefore, it is important to upgrade the anti-virus system version and install patches in time.

As a carrier of information, the Internet is getting more and more attention. The rapid development of information technology, the number of network users and information is increasing rapidly, the pressure on the network is increasing, and people's requirements for network speed are getting higher and higher. The main factors affecting the speed of the network should be taken as a basic common sense to be grasped by ordinary users to help users better use the network and obtain network information more easily. Network bandwidth is the basis. Network bandwidth refers to the amount of data that can be transmitted in a unit time (generally 1 second). Insufficient bandwidth or excessive load to connect to the target website server will definitely limit the network speed.

Bandwidth is the transmission rate, which refers to the maximum number of bytes transmitted per second (MB / S means how many megabytes are processed per second). High bandwidth means the high processing capacity of the system, just like a highway lane The greater the bandwidth, the more lanes. Network routing devices, network cards, graphics cards, etc. all have their own bandwidth, and the bandwidth between network layers must be matched without bottlenecks. The main network switches in the conventional network topology are divided into core switches, distribution layer switches, access layer switches, and hubs (HUBs). Information throughput is reduced step by step, bandwidth can be reduced step by step, and selection or matching is not reasonable. Network bottlenecks naturally occur.

Processing speed network lines

Network lines are usually divided into optical cables and twisted pair cables. The impact of optical cables is relatively small. Twisted pair cables must be manufactured strictly according to specifications. Twisted pairs are tightly twisted together by four pairs of wires in accordance with strict regulations to reduce the effects of crosstalk and background noise. At the same time, in the T568A standard and T568B standard, only four wires of twisted pair 1, 2 and 3 and 6 are used. Among them, 1 and 2 are used for transmission, 3 and 6 are used for reception, and 1, 2 must come from a twisted pair. Yes, 3, 6 must come from a winding pair. Only in this way can crosstalk be avoided to the greatest extent and data transmission can be guaranteed. The standard production of network cables is very important.

After the production of the network cable is completed, a standard tester is used for testing. If the indicators such as insertion loss, return loss, near-end crosstalk, and far-end crosstalk fail, the network speed will be affected. The quality of the twisted pair must meet the national standards. The RJ45 header must be remade if the network cable is not qualified. When the electromagnetic signal interference of the line is serious, consider using a shielded twisted pair or changing the line direction.

Handling typical network connection failures

When the number of nodes involved in the network is small and the structure is relatively simple, this phenomenon rarely occurs. However, in some more complicated networks, there are often redundant backup lines, which will form a loop if they are inadvertently connected. For example, the network cable is connected to the computer room 1 from the network center, and then connected to the computer room 2 from the computer room 1. At the same time, a backup line from the network center is directly connected to the second room of the computer. If these lines are connected at the same time, it will form a loop. The switch, the computer two-room switch, and the computer two-room switch are connected to the switch port, and then back to the network center switch. At this time, the network center switch thinks that the source address is a port of the network center switch, and the destination address is another port of the network center switch. This causes the network center switch to send data packets to itself, causing self-excitation, which affects the overall network speed ^[1] .

Finding this situation is more difficult. In order to avoid this situation, we are required to develop good habits when laying network cables: the network cables are marked with obvious labels, and where there are spare lines, we must make a record. When such a failure is suspected, the method of gradual elimination by partition is generally adopted. From the perspective of network design, in order to prevent such failures from affecting the overall network, a manageable switch should be selected, and different network segments should be used in different areas to effectively prevent such failures and reduce the scope of troubleshooting.

Handling speed network viruses

The impact of viruses on network speed is becoming increasingly serious and extremely harmful. This virus causes infected users to continuously send out emails as soon as they surf the Internet. The virus selects random files in the user's personal computer to attach to the user's computer's address book for random mail sending. Hundreds of thousands of such spam emails were sent out in line, while others were returned in batches and piled on the server. As a result, individual backbones have noticeably congested the Internet, the network speed has slowed down significantly, and the LAN is nearly paralyzed. Therefore, we must upgrade the anti-virus software used in a timely manner; the computer must also be upgraded in a timely manner, install system patches, uninstall unnecessary services, and close unnecessary ports to improve system security and reliability.