When connecting your smartphone or development device to your computer, have you ever thought,
“Why is the transfer so slow?” or “Why am I getting connection warnings?”
One often overlooked cause is the cable’s specifications. Even if two USB cables look identical, their internal structure and supported standards can make a huge difference.
This time, I tried using a USB cable tester to see how we can easily check a cable’s actual specs.
🤔 What You Can Learn with the Treedix USB Cable Tester
The tool I used is the Treedix USB Cable Tester Board, which supports multiple connector types such as USB-A, Type-C, and Micro-B.
It can test both data transfer and charging performance — a very handy little board.
👉 Treedix USB ケーブル テスター ボード USB ケーブル チェッカー データ ワイヤ 充電 テスト データ ライン タイプ C – Treedix Official
👉 TREEDIX USB Cable Tester Manual - Test USB Cables for Charging and Data Transfer
According to its manual, if the LEDs for “High-Speed Charging” and “High-Speed Data” light up, it means the cable supports USB 3.x.
If they don’t light up, the cable is only USB 2.0 level.
In short, this tiny board lets you instantly “see” the invisible differences inside your cables.
🤔 Test Results: USB 2.0 vs USB 3.x
First, I tested the cable I had been using regularly — and it turned out to be USB 2.0.
Apparently, it was almost a charging-only cable with no proper data lines.
Next, I tested a recently purchased Buffalo cable. This time, the USB 3.x indicators lit up clearly, confirming that it supports high-speed data transfer.
When I switched to this cable for connecting my Android device to Android Studio, the connection warnings disappeared completely — the link became much more stable.
However, I didn’t feel much difference in actual transfer speed, suggesting that other factors (like device or build performance) may be the real bottleneck.
🤔 Conclusion: Visualize Your Cables for Peace of Mind
A USB cable isn’t “just a wire.”
Its performance depends on which internal signal lines are actually connected.
Using a cable tester lets you easily determine whether your cable is charging-only, data-transfer capable, or high-speed compatible.
Especially for developers or anyone who needs a reliable connection, it’s worth testing your cables at least once.
Once you understand what’s inside, you’ll choose better cables and avoid unnecessary frustration in the future.
👉 実機デバッグで出る「Connection speed warning」とは ⚡
関連ワード: Android・AndroidStudio・apple・Google・iPhone・Pixel