Technology: The (nearly) perfect USB cable tester does exist

Summary

As probably everyone reading this blog, I have a lot of USB cables. I want to sort and categorize them. What the cable can and cannot do is an important factor. But how do I really find out what a cable supports? As I found out during this quest, your cable may successfully lie to your PC. Previous attempts I always thought: The perfect USB cable tester doesn’t exist. Unitl now I used a cable tester that used LEDs that show the status of a USB cable. This came with one major annoyance: every time I had to retrieve the manual what that specific pattern implies. At least for USB C cables I thought I had found a very clever way to determine what speed was supported: I used it to connect a device that supported 20gbps (e.g. a SSD) Then I looked up what system_profiler SPUSBDataType on macOS told me about the connection speed. At that point I discovered: my cables keep lying to my PC. The cable tester showed that a speed above USB 2.0 was physically impossible, but macOS still was happily reporting to have that disk connected with 10gbps. Some tests reading/writing that disk confirmed that “something is rotten in the state of Denmark USB.” The Treedix USB Cable Tester with 2.4" Color Screen Then one day I stumbled over the Treedix USB Cable Tester with 2.4" Color Screen. It pressed all my buttons: wide range of supported plug types, clear and easy to parse information and a real deep dive what your cable says it does. Power supply is either a AAA battery or through an external USB C cable on a dedicated port. I guess that port also allows to update the system although all hints on that were just some posts on Reddit. What kind of cables can it check? Side A: USB-A or USB-C Side B: USB-C, Mini, Micro, Micro-B The device has a mode button with which you can cycle through different modes: Data and Power modes: Connected lanes: Resistance values: Cable eMarker This is pretty easy to understand… or so it seemed. My experience Then I started rating my cables. One of the cables...