My MacBook air was bought in early 14th, and the previous Thinkpad T400 was stolen in the 13th summer vacation! However, Thinkpad T400 also completed his historical mission and did a lot of things during college. Said more meat hurts, after all, is spent 9,999 yuan to buy a student machine with high in 2009, full of memories! At that time, buying air was really hot, and the only advantage of using it was that it was lighter and easier to go out. But the performance can only be lightly worked, p maps. Just work relatively poor, so bought a 13-inch low air: 4G memory, 128GSSD. Here we recommend that you buy 8G memory, because the memory is soldered on the motherboard, can not be upgraded. The hard disk space can be expanded through the built-in SD card slot later. Because of the need for office convenience, with a dual system installed, 128G space gradually became insufficient. A few days ago someone wanted to copy a good 36G film to see me, and the result was direct, space is not enough, can only watch the film tears. In order to prevent this from happening again, you must expand your storage space. First of all to buy a TF card to SD card sets, buy links: This card set is very cost-effective and mainly cheap. Only a silver arc is highlighted on the air, and the matching is still good. According to the evaluation of other online buyers, the card sleeve should be about 7.5mm on the pro model, which is ugly: It is recommended to buy a little expensive, recommend: This card sleeve work in general, there is no detail, the highest only supports 64G TF card, but think about the price will be considered, 9.9 can still God After buying the card cover, the next step is to buy a card. The Majia water is too deep, or go to the tea house to buy it. Samsung is more reliable. Samsung's work is still possible. The bullets crashed Come and come, papapa! Oh, not bad. Capacity 63.99G, no shortage of two Speed ​​measurement software: Disk Speed ​​Test, ATTO Disk Benchmarks Speed ​​environment: computer USB 3.0 interface 1, Disk Speed ​​Test U disk read is 85.7M / s, write is 25.5M / s. I heard that this software is hurting the hard drive, scared me almost lost the hard drive 2, ATTO Disk Benchmarks test U disk maximum read is 88.7M / s, the maximum write is 28.1M / s. Taken together, the reading speed should be around 85M/s, and the writing speed should be at 25M/s. Meets Samsung's official promotion speed. Advantages: Dual system can put some common data files on the TF card, so that there is no need to switch off the system. The data file synchronization between the two systems is very convenient. Disadvantages: 1, only support 64G TF card, the capacity is generally like, only suitable for light office. 2. In the Win system, if the system goes to sleep and wakes up again, it will not recognize the TF card. This is a pit. Fortunately, usually usually use the Mac system. To sum up, this solution is not one-step capacity expansion, after all, only 64G expansion capacity, but it is more economical ~ Optical Line Terminal (OLT)
POE (Power Over Ethernet) refers to the use of IP-based terminals (such as IP phones, wireless LAN access points AP, network cameras) without any changes to the existing Ethernet Cat.5 cabling infrastructure. Etc.) The technology that can provide DC power for such devices while transmitting data signals is a switch that supports Power over Ethernet.
POE is also known as a power supply system based on local area network (POL, Power over LAN) or Active Ethernet (Active Ethernet), sometimes also referred to as Power over Ethernet for short. This is the use of existing standard Ethernet transmission cables to transmit data and data at the same time. The latest standard specification of electric power, and maintains compatibility with existing Ethernet systems and users. The IEEE 802.3af standard is a new standard based on the POE of the Ethernet power supply system. It adds related standards for direct power supply through the network cable on the basis of IEEE 802.3. It is an extension of the existing Ethernet standard and the first international standard for power distribution. standard. Ethernet Poe Switches,Din Rail Mount Switch,Gigabit Din Rail Poe Switch,Managed Port Industrial Switch Shenzhen Scodeno Technology Co.,Ltd , https://www.scodenonet.com
IEEE began to develop the standard in 1999, and the earliest participating vendors were 3Com, Intel, PowerDsine, Nortel, Mitel and National Semiconductor. However, the shortcomings of this standard have been restricting the expansion of the market. Until June 2003, the IEEE approved the 802.3af standard, which clearly stipulates the power detection and control items in the remote system, and connects routers, switches, and hubs to IP phones, security systems, and wireless LANs through Ethernet cables. The method of power supply for points and other equipment is regulated. The development of IEEE 802.3af includes the efforts of many company experts, which also allows the standard to be tested in all aspects.
The IEEE 802.3at standard was formulated in 2005 and promulgated in 2009. The 802.3at standard output power can reach 30W, and the available power at the receiving end is 25.5W.
The IEEE 802.3 working group and various manufacturer alliances launched POH-POWER OVER HDBASET in the industry at the end of 2012.
Using the current 4-Pair four-pair wire technology plus, the bilateral power supply can reach 60-100W power, which can be achieved by using 5 or 6 types of wires. It is used in high-definition video promotion to supply power to 42" LED TVs. According to the new regulations in 2010, the power consumption of 42" LED TVs needs to be less than 70W.