What is the difference between Category 5e and Category 6 network cables? Don’t blame the router if the Gigabit speed is not satisfied. I cut three wires to see clearly.

Last year, my family upgraded from 300Mbps to Gigabit, and the router was also replaced by Xiaomi AX3000T. I thought the speed test should be better this time. After testing, the desktop computer in the study room still only had more than 300 MB. I was so angry that I changed the positions of the optical modem, router, and mobile phone one by one. It took me two days to remember: The network cable buried in the wall was a Category 5 cable that the master bought during the renovation. It is this cable that keeps my Gigabit broadband at over 300 Mbit/s. Today, I will settle the accounts for several types of network cables at once, so that you will not have to dismantle the router in vain like me.

First distinguish: What are the differences between Category 5e, Category 6 and Category 6e?

Network cables are divided by category. Just look at the words printed on the cable skin.: CAT5E is Category 5e, CAT6 is Category 6, and CAT6A is Category 6e. If there is an extra word "super" in the name, the performance will be worse. There are only three cores: Bandwidth, wire diameter, skeleton.

The smaller the AWG number, the thicker the line. 24AWG is thinner than 23AWG and contains less copper. It suffers from interference resistance and voltage drop when running at high speeds over long distances. The cross frame in the middle of Category 6 is not a decoration. It separates the four pairs of lines and reduces crosstalk. This is why it can stabilize Gigabit. There is also Category 7 CAT7, which has a bandwidth of 600MHz, but the connector does not use ordinary crystal connectors, and is basically not suitable for home use. Don’t be fooled into spending more money by “Category 7 is more advanced”.

It has to be said in passing whether it is shielded or not. In an ordinary home environment, UTP unshielded Category 6 is enough. ； FTP/SFTP shielded lines should only be considered when the lines are close to strong electricity, running in air-conditioned equipment rooms, or buried in pipes alongside a bunch of wires. Both ends of the shielded wire must be grounded. If not connected properly, it will turn into an antenna, which is worse than being unshielded. This is a pitfall that many people don't know.

There is another confusing point: Category 5e does not mean "it can only run at 100 Mbit/s". In the standard, Category 5e also supports Gigabit within 100 meters, but the anti-interference margin is small. When short jumpers and wires are up to standard, there will be no problem running Gigabit over Category 5e. ； The real hindrance is the old Category 5 CAT5, inferior copper-clad aluminum, or the distance is too long.

The scene where I was dissatisfied with my gigabit speed

At first I thought it was the router that wasn't working. AX3000T is connected to the optical modem, and the mobile phone is placed against the router. The test is about 940 Mbit/s, which seems to be no problem. But when I tested the desktop computer in the study, there were only over 300 left. I replaced the line between the router and the optical modem with a newly bought Category 6 jumper. Then I connected the network port on the wall of the study to the desktop, and it still cost more than 300.

Finally, I used a line tester and a notebook to rule it out step by step, and found out that it was the line in the wall from the weak current box to the study during the decoration. The line printed on the line was CAT5, not CAT5E, but the older pure Category 5. Category 5 lines theoretically only reach 100 Mbit/s, and more than 300 Mbit/s is considered to be an extraordinary performance. I couldn't tear down the wall and pull out this line again, so I finally took the baseboard open line and pulled out a Category 6 line. The desktop speed test returned to around 930 Mbit/s. Even the 5G speed test of the mobile phone increased from more than 400 to more than 900. Only then did I confirm that the fault was really not with the router.

Therefore, if the gigabit speed test fails to meet the standard, don’t blame the router for now. Gigabit broadband WiFi speed test is only 600 megabits I wrote in that article that bandwidth, negotiated speed, and measured speed are three separate accounts. But the underlying account is: From the optical modem to the router, and from the router to the computer, every network cable in between must meet the standards. A single Category 5 cable can drag the entire link back to the 100M level. The network port negotiation speed is the best way to check. Click on the "Link Speed" in Windows Network Settings to see if it is 1000Mbps. If it is only 100Mbps, it is probably the fault of the cable or crystal head.

You can recognize it at a glance from the line printing.

Don't just listen to the seller saying "this is a Gigabit cable", look at the cable skin. There is usually a long list of words printed on the thread skin, focus on these few:

• CAT5E: Category 5e is common in old houses, and Gigabit is fine for short distances. ；
• CAT6: Category 6, the first choice for home Gigabit ；
• CAT6A: Category 6e, for 10 Gigabit long distance use ；
• 23AWG or 24AWG: 23AWG is thicker and better ；
• UTP is ordinary unshielded, FTP and SFTP are shielded.

There are often a series of meter marking numbers on the thread, which jump every one meter. This is a mark from a regular factory and can also help you measure the distance. See, this string of words also has a practical meaning.: Some "Category 6 cables" are actually Category 5e cables with a tare weight printed on them. You can reveal the truth by measuring the wire diameter with a caliper. The diameter of a single copper core of true Category 6 is about 0.57 mm, and that of Category 5e is slightly thinner. ； If you still can't, cut it open and see if there is a cross frame in the middle. There are basically six types, and you can recognize them at a glance.

The three most common pitfalls when buying threads

The first pitfall is copper-clad aluminum and copper-clad iron pretending to be pure copper. The cut section of pure copper wire is bright copper in color, the section of copper-clad aluminum is white in the middle, and the copper-clad iron section is exposed when you hold it with a magnet. Copper-clad aluminum has high resistance and will lose speed when running at high speeds for long distances. Over time, it will easily oxidize and break. The price difference is also very direct: Copper-clad aluminum can be sold for 56 cents per meter. Oxygen-free copper type six normally costs 1.5 to 2 yuan per meter. If it is too cheap, it is probably a scam. I advise you to buy the right home buried wall cable at the first time. Don’t demolish the wall after a few years just to save dozens of dollars.

The second pitfall is that the crystal head and panel do not match. Many people have upgraded their cables to Category 6, and even buy Category 5 heads for crystal heads. The Category 5 crystal head has a small aperture, and forcing a Category 6 cable into it can easily crush the core of the cable. When buying a crystal head, make sure it is CAT6, and the panel module is the same. How to connect the crystal head of network cable I defeated six of them before I could figure it out. Memorizing only the T568B line sequence is enough.

The third pitfall is distance. A single section of 100 meters of network cable is a standard dead line. If it exceeds 100 meters, the speed will be reduced and packets will be lost. How many meters can the longest network cable be? In that article, I pulled a 130-meter car rollover record. When decorating a buried wall, remember to add a 90-meter permanent link and 10-meter jumpers at both ends. For long distances, you either need to add a switch in the middle or directly connect the optical fiber. The difference between optical fiber and network cable In one sentence, one beam transmits light and the other transmits electricity.

Which one should I choose at home? Three kinds of people copy homework

For an elderly room with pure Internet access and 100 Mbps broadband, Category 5e is enough, and short jumpers can run Gigabit without any problem. Don’t be superstitious that the more expensive the better. Ordinary households with gigabit broadband can choose Category 6 without any thought. The price is not much more expensive than Category 5e. All buried walls, jumpers, and panels use CAT6, which saves worry. For those who have a NAS 10G intranet, a gaming room, or those who plan to upgrade to 2000M or 10GbE in the next few years, directly connect the Category 6A shielded wires buried in the wall to get it right in one step and avoid having to tear down the wall later. Compromise if budget is tight: Use Category 6 when buried in the wall. Use Category 6 for the short jumper between the NAS and the computer. If you really need 10G, then use Category 6A separately.

There is also a type of people who have "already finished decorating". If the wall is Category 5 or Category 5-plus, don't despair yet. Most short-distance Category 5e Gigabit tests can reach more than 900. Let’s test it first before talking about it. ； If it really doesn't work, just use exposed threads like me. You can hide them in baseboards, door frames, and behind curtains. How to plan network cable decoration For the positions discussed in this article, open thread remedies can also be used. Don’t force the panel wiring, the module wiring should be stuck according to the color code. How to wire the network cable socket panel The first one broke off the cord cover.

Summarize: Check the Gigabit cable first, don’t disassemble the router first

List the order in which I stepped on it: First check whether the cable is CAT5E or CAT6, measure the cable diameter, and then check on the computer to see if the negotiated rate of the network port is 1000Mbps. ； Gigabit broadband is Category 6, and the crystal head and panel are replaced with CAT6 ； For 10 Gigabit, long-distance, and NAS intranets, consider Category 6e or optical fiber. Network cables are something that "can't be seen at ordinary times, and everything happens to them". A substandard cable can wipe out all the money you spent on upgrading your router, optical modem, and mobile phone. After changing the cable, my study desktop jumped from more than 300 to 930. It only cost me 20 yuan for a Category 6 cable, which is much cheaper than replacing a router. Find out the thread first, and then talk about anything else.