superscan811:
Being able to set when it updates would be preferable (ie: you could set each to sync 1/5 phase from each other).
No, they are synchronized to the atomic clock on the satellites.
Most GPS devices can be configured to provide updates at 5hz or more.
Why do you need it?
You might be interested in my NeoGPS library. It's smaller, faster, more reliable and more accurate than all other GPS libraries.