Review on 💻 Expand the USB Power and Efficiency with FebSmart PCIE 4-Ports Superspeed 5Gbps USB 3.0 Expansion Card for Windows Server XP Vista, 7 8.x 10 (32/64bit) Desktop PC-Build in Self-Powered Technology-No Need Additional Power Supply (FS-U4L-Pro) by Jesse Diaz

This thing was causing my self-sufficient drives to spin down regularly. If they were powered from the USB port I would see them not working properly all the time. These are desktop-sized external drives that have their own power supplies. If you connect directly to a computer or hub using one of the onboard ports, you'll be fine. If they are on this map, they will be disabled. I tried two cards and both had this problem. If you are looking for a totally unreliable card, then this is it! (Note: I'm an IT professional, this is a card issue, not a user issue.)