Bests & Worsts Reviews from Amazon

If you think the cable you buy makes only slight difference to your data transfer speed, you are absolutely mistaken. The truth was made clear to me when I bought this CONMDEX brand 2-cable pack. I have a MacBook Pro, 13-inch, mid-2014, with a Western Digital 2TB external “My Passport” SSD connected by an ANKER brand USB 3.0 to USB C cable, 1m in length. The computer has two USB 3 ports, and the external SSD has a USB C port. Since I have a second “My Passport” external SSD and only one of the ANKER cables, I went shopping for a second cable. I encountered the CONMDEX cables, packaged two 1m cables in a pack at a very low price. Throughout the Amazon ad for the cables the big stress was on speed. As soon as my new cables arrived, I eagerly conducted a speed test to see just how much speed increase I had purchased. I set up two copies of a folder on my computer that contained many internal folders and files of varying types of data. The total data size was 22.66GB. Then I timed the transfer speed of copying the 22.66GB to my external WD SSD via my older ANKER cable — 1 minute, 4.66 seconds. Then a test repeat with the same ports connected this time by one of my new CONMDEX high speed cables — 10 minutes, 56.58 seconds. I couldn’t believe it — more than ten times as long! Considering that I must have been somehow inconsistent in my cable connections, I conducted the same series of tests three more times, including using the other USB 3 port on the computer. I got almost identical times with each test. The old, slow cable always transferred the data in less than 1/10 the time of the new “fast” cable. My review of the CONMDEX ad on Amazon reveled that the cable is specified to have “extensive compatibility” with a list of products that does not include MacBooks nor Western Digital SSDs. So, if you have a Western Digital SSD or a MacBook, you should not be buying this CONMDEX cable if you are in need of speed. Be sure to check the list of extensive compatibility before you buy. For my use, I would give these cables only one star for snail speed, but all the other characteristics of the cables seem to me to be of good quality, so I added a second star. They may actually be of five-star rating if your equipment is on the compatability list -- read the small print in the ad.