Ethernet cables are about as simple as they get. They're the easiest, most reliable way to connect a desktop PC to the internet. In the vast majority of cases, you just have to plug the cable into your PC, and just like that, your computer is connected, no configuration necessary.
However, things can get a little complicated when an Ethernet cable isn't up to snuff. Logically, you'd think that they either work or they don't like virtually any other computer cable, but that's not always the case. Ethernet cables can work just fine on the surface while quietly throttling your speeds. That's exactly what happened to me, and thankfully, it was actually quite easy to troubleshoot.
It all started as a "simple" cable that should've taken five minutes
A quick upgrade that didn't go as planned
If you're curious why I wanted to "upgrade" my Ethernet from one gigabit cable to another, it mostly came down to moving my router from my bedroom to my kitchen. A router's Wi-Fi signal is only as good as its placement, and since my kitchen is pretty much the center of the apartment and where the ISP's modem is located anyway, it was the most logical place to relocate the router.
The only problem was that I had to fish a new, longer Ethernet cable from the kitchen all the way to my bedroom, and the only way to do that in an apartment with concrete walls was by routing the cable under the kitchen carpet, sofa, through the wall directly, and then next to my bed to reach the PC.
To keep things clean, I opted for a flat Ethernet cable rather than a traditional round one, so it would be barely noticeable under the carpet.
Routing the cable under the carpet and sofa was easy enough, but I ran into some difficulty pushing it through the hole in the wall, which was just barely wide enough. It took a few minutes, some bending, and a bit of force to get the cable through, but when I was done, nothing appeared damaged on the surface. I plugged it into my PC—and I was off to the races. Or so I thought.
Something felt off, but nothing was obviously broken
Subtle slowdowns are easy to miss
Ismar Hrnjicevic / How-To Geek
I didn't notice the slowdown at first. I honestly just assumed the cable was working fine because I had an internet connection, and regular web browsing felt fine for the most part. My internet speed tops out at only 200 Mbps, so I'm already used to mediocre speeds anyway.
The first time I noticed something was off was when I started downloading a video game upgrade on Steam the day after swapping out the cable.
I rarely pay attention to download speeds, since they can vary depending on a number of factors, but what felt strange was that web browsing practically slowed to a crawl—slower than the usual loading speeds I get while downloading something. Another hint came when I was transferring images from my phone to my PC using Microsoft Phone Link .
These transfers normally take around a second per image because their speed is only limited by your LAN setup (which is around 700Mbps for my 5GHz Wi-Fi connection), but for some reason, ten photos took about a minute. Needless to say, something was off with my internet connection, and the brand-new cable quickly became my first suspect.
Testing my internet speed and checking network settings helped me pinpoint the problem
A missing digit revealed the truth
The first thing that came to mind when inspecting my internet connection was, of course, to run an internet speed test . It's far from the most reliable way to check an Ethernet cable ( or even internet speeds ), but I figured it'd give me a rough idea of where I was standing—and it did. Instead of sub-200 Mbps internet speeds, I only got sub-100 Mbps.
To confirm that my Ethernet cable was bad, I headed over to Start> Settings> Network & internet> Ethernet. And there it was. Instead of seeing 1000/1000 (Mbps)under Aggregated link speed (Receive/Transmit), I was limited to just 100/100 (Mbps).
This effectively meant that my Ethernet cable was defaulting to the ancient 1995 Fast Ethernet standard, which is a tenth of a gigabit network.
The reason this happened is most likely because I twisted the flat cable too much when I was routing it through the wall. The ultra-thin copper wires inside an Ethernet cable can break easily, and if even a single wire of the eight (four twisted pairs) that an Ethernet cable has is damaged, the cable drops speeds to 100Mbps, as Fast Ethernet can work on only four wires.
Replacing the cable was cheap and easy
The world's easiest fix
Although flat Ethernet cables are great for hiding under carpets and furniture, they're significantly less durable than traditional round ones. Of course, the quality and thickness of the insulation and the wires inside matter as much as the cable form factor, and my flat cable was among the cheapest I could find. If you opt for a flat Ethernet cable, avoid sharp bends and kinks, particularly near the connector.
Since Ethernet cables are very cheap, I bought a new one as soon as I discovered the problem to replace the broken cable. Just like that, I was back to gigabit Ethernet speeds.
You don't need fancy tools to spot a bad Ethernet cable (but they help)
Basic checks are all you really need
While I wasn't happy about breaking a brand-new cable that I had spent twenty minutes installing, I'm glad I didn't have to spend big bucks on an Ethernet cable tester just to identify the problem.
While those tools are a great investment because you can troubleshoot without relying on a PC, and you can also use them if you want to fix a broken cable instead of replacing it, sometimes the tools built into the operating system are all you really need.
