On Sun, 2020-02-02 at 13:32 -0800, John Jason Jordan wrote: > On Sun, 2 Feb 2020 13:11:28 -0800 (PST) > Rich Shepard <[email protected]> dijo: > > > I should have known that USB ports have limited power supply > > capabilities. My external optical drive (used for the Dell 2100 and > > ThinkPad X200) has two USB cables, one for power the other for data. > > I also have an optical drive that came with a cable like that. I could > never figure out which fork was data and which was power, and then I > wondered if it was using both for power. > > It was advertised as being USB 2.0. The interesting part is what happens > when I plug it into a USB 3.0 port. (None of my computers have USB 2.0 > ports any more.) Not only does the drive not need both forks inserted, > it also doesn't seem to matter which one I use.
On the contrary - all of your ports are usb3 and also usb2 - it is part of the compatibility spec for the root device to have both 2 and 3 controllers hanging on the USB-A connectors. For hubs - that may be different - although after brief period when usb3 was new - most likely all hubs are 2 and 3 these days. > _______________________________________________ > PLUG mailing list > [email protected] > http://lists.pdxlinux.org/mailman/listinfo/plug _______________________________________________ PLUG mailing list [email protected] http://lists.pdxlinux.org/mailman/listinfo/plug
