My laptop has only two USB ports: one is usually occupied by a printer, and the other is used by my mouse because I prefer it over the touchpad. I also use a small USB humidifier while working, and occasionally need to connect a USB flash drive, so I'm constantly swapping devices.
I'm considering buying a USB hub, possibly alongside a Bluetooth mouse. Would my laptop recognize and allow me to use a mouse and USB flash drive at the same time through one USB port? Also, would sharing the port cause noticeable mouse lag or other performance problems? The humidifier only needs power and doesn't need to communicate with the laptop.
3 Answers
A mouse shouldn’t lag just because it’s connected through a hub. USB bandwidth and power are shared, but a mouse uses very little of either, and a flash drive generally won’t cause a noticeable problem during normal use. A powered USB hub is a good choice if you’ll be connecting several devices or anything that draws more power.
Since the humidifier only needs electricity, you don’t necessarily need to connect it to the laptop at all. A USB wall charger or power brick would free up a port and avoid adding its power demand to the hub.
What you want is a USB hub rather than a splitter. Plug the hub into one laptop port, then connect the mouse, flash drive, and other peripherals to the hub. The laptop should detect each device separately, so you can use the mouse and flash drive simultaneously.

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