My Acer Cloudbook trackpad is I2C, a similar simple bus. It can be configured in BIOS to fallback to PS/2 with reduced capabilities. PS/2 is too slow for the v

My Acer Cloudbook trackpad is I2C, a similar simple bus. It can be configured in BIOS to fallback to PS/2 with reduced capabilities. PS/2 is too slow for the volume of data coming out of a modern touchpad. USB is a lot more hardware, though that is small in the context of a CPU. It may just be that with I2C running around the motherboard for all the miscellaneous devices it just makes sense to use that.