The speed at which the
gpsd updates is dependent on the speed of the device it is polling for location and the reception that device has with regard to the satellites.
GPS signal is very weak and works best outdoors with a clear line-of-sight with the sky. The GPS device that
gpsd polls uses the signals from several GPS satellites to compute a location and then passes that information on to the
gpsd daemon at a fixed rate (in some cases, once per second).
I would recommend reading the documentation about
gpsd. If performance is your biggest concern, might I suggest a whitepaper analyzing the performance of
gpsd and several GPS devices?