How much of PC laptops' touchpad quality is due to hardware limitations? I seem to recall back when I owned an Apple laptop (circa 2010) that its trackpad was connected internally via USB. Meanwhile, PC touchpads almost universally used PS/2 which provided far lower bandwidth. Is this still the case?
The Microsoft Precision Touchpad[1] devices are interfaced over I2C or USB. Bandwidth for I2C depends on implementation AFAIK, but should be plenty for a responsive touchpad.
Yes and no. Some trackpads are connected over actual PS/2, but others via the EC and that one simulates PS/2 internally. On the MacBook side it's SPI now, not in all cases, but pretty often. Not sure if it's a Double or Quard SPI interface but apparently it still does the same nice experience they had with USB - and better.
