HTTP://TIEBA.BAIDU.COM/P/3086867101 Wireless card is everyone to buy a computer is easy to ignore the link, especially the frequent use of high-speed bandwidth access to users, a high-end wireless network card with a corresponding high-end wireless router, There is no big problem in replacing the wired network in the case of fewer people. ThinkPad because it is business, especially T X W series, basic can be equipped with the highest end of the wireless network card, but a lot of low-matching machine network card shrinkage, resulting in many friends around the stalls, buy high-end machine, only with 1x1 crab card, this tragedy often occurs, there are people who see the bar stick High-end network card, But will not use, spit groove machine, really can't see, write something useful to everyone.
First wireless network and wired network is different, wireless network is a conflict domain, the more people, the actual usable total bandwidth will be smaller, there is the same frequency interference and other factors, the actual use of the speed is difficult to generalize, so the following I said the situation is based on the basic signal good, There is no same frequency conflict (the wireless environment is relatively clean) in the case of the typical speed, this value basically you hold your computer near the router in the case of the same frequency interference is not too large to click on the network properties can be seen, very intuitive.
To put it simply, the simplest way to differentiate a NIC is to differentiate it by the maximum negotiation speed. Simply say that my wireless network card can reach the maximum negotiation speed (negotiation speed is not the actual download speed, negotiation speed can be simply understood as the maximum theoretical speed, the actual speed is generally much smaller than the negotiation speed), at present, we can see the typical maximum negotiation speed of the following several, 54M 72M 144M 150M 300M 450M 867M (basically very neat)
Say the exact meaning
Maximum speed achievable under the 54M 802.11b specification
(11b technology does not support MIMO, unable to bind the channel, the bandwidth is very low, has been eliminated, the market is difficult to buy such network cards)
72M 802.11n specification, the maximum speed can be achieved under the single Mimo,20mhz bandwidth
(at present, a lot of machines with crab card, typical is X220 T420 and some other machines with Realtek BGN 1x1 network card, this type of network card in the 40Mhz bandwidth is not open when the speed, want to speed up, it is recommended to switch on the network card and router on the 40Mhz bandwidth settings, Speed up to 150M after opening)
144M 802.11n specification, 2x2 MIMO, 20Mhz bandwidth below the highest possible speed
(A 2x2 MIMO-enabled NIC is at least a midrange NIC, typically with Intel's 6200 series X220 T420 This generation of machines and now the latest T440 X240 Intel Dual Band wireless-n 7260 and Intel Wireless-n 2200, want to speed up is also very simple, with the above 72M, as long as the 40Mhz bandwidth can be increased to 300M)
150M 802.11n specification, the maximum speed can be achieved under the single Mimo,40mhz bandwidth
(A very common speed, most handheld 11n devices, can be achieved, see 72M instructions)
Under 300M 802.11n specification, the maximum speed that can be achieved under the 2x2mimo,40mhz bandwidth
(also more common speed, see the 144M description, can achieve this speed and above the equipment recommended using the 5G band, this will say)
Under 450M 802.11n specification, the maximum speed that can be achieved under the 3x3mimo,40mhz bandwidth
(can achieve this speed of wireless network card very few, the most typical is X220 T420 this generation of machine with Intel's 6300 to three antennas at the same time to achieve this speed, is the 11n era notebook the highest speed, if not open 40Mhz bandwidth, negotiation speed will fall to 216M)
Under 867M 802.11AC specification, the maximum speed that can be achieved under the 2x2mimo,80mhz bandwidth
(802.11ac is the latest wireless specifications, due to the use of a larger bandwidth, so in the case of 2 antennas can be substantially beyond the 11n below the speed of 3 antennas, can reach 867Mhz high speed, the typical product is now T440 X240 above the use of the Intel Dual Band Wireless-ac 7260 is currently the flagship product, but this type of high speed can only be achieved under the 5Ghz band)
Another: Some people may say, my home bandwidth is limited, 54M is enough to use, high bandwidth is useless, in fact, I said, those are only negotiated rate, the actual use of the entire wireless system throughput, delay or even signal, may be due to different negotiation speed, even if your home only 6 m broadband, It's likely that after you switch to a high-end wireless card and a relatively good router, your ping packet latency is significantly reduced, the signal is significantly increased (multi-MIMO is very helpful for lifting signals, single-MIMO network card signal and stability is a soft rib),You know, the most important thing that affects the Web experience is latency and stability rather than the highest rate of the so-called download.
Suggestions:
1. About band selection
Due to the serious shortage of 2.4G band resources, only 3 non-overlapping channels, interference is very large, and look at the above you will find that the pursuit of high bandwidth is basically going to open 40MHz frequency, in fact, the so-called 40Mhz frequency-width principle is very simple, a channel bandwidth is 20mhz,40mhz bandwidth is to be adjacent to the two channels bound up to high swallow Amount of spit, However, the 2.4G band is only 3 independent channels, you use two channels, the surrounding as long as there are other hot spots, you will have a great deal of interference to your wireless system, will lead to your actual use of the experience is not ideal, so strongly everyone has the conditions to choose the 5Ghz frequency band, simply said the 5Ghz frequency channel more, and the use of fewer people Almost no interference, with the latest wireless technology to achieve ultra-high speed, the earliest 802.11ac in the draft phase was originally to abandon the 2.4G band, and later compromised to restore support for 2.4G. It can be said that the future mainstream WiFi will be 5G this high frequency segment.
2. About NIC Selection
There are many types of network cards on the market, but basically in the ThinkPad system, the high-end is Intel's network card, Intel's network card is more stable than other brands, we buy the network card when you leave a mind to look at, and generally buy high-end machine users, the conditions of the best choice of Intel Dual Band Wireless-ac 7260 This card, the reason is very simple, the machine cost is similar, this card buy only 200 more, but wireless performance will be much better, buy low with machine friends, also try to avoid non-Intel network card and the kind of 1x1 MIMO card, buy before doing homework, Online Check the network card model again shot
3. About routers
Wireless is a system, not independent. Requires a machine card and router to play with the high-speed, any link is not set up, will make your wireless system spin down. When the machine is slow, do not just focus on the driver and the like, the router to check the good, low-priced routers will not have a good performance. Preferably with their own wireless network card to purchase the router, do not appear to use the top-level AC network card, but also in support of only 11b technology router this situation. My advice is to match the router and NIC specifications, assuming that you're using a 2x2 MIMO 11n wireless card to buy a router that supports at least 2x2 MIMO, so it doesn't become a bottleneck. According to the current market price such routers are also 200 less than.
In addition 11AC is a new thing may not be used in many people, this is required to set up the high-speed mode, I today, I toss a bit, 11AC high-speed mode is required to manually in the configuration of Intel network card, otherwise only 11n speed, how to open the specific look
Select VHT Mode to
After opening, can reach far beyond the speed of 11n (in the case of a door, the limit is 867M)
About wireless card speed Popular Science
