Time quantization when reading from serial port

[Chris Stankevitz]

I receive data on the serial port (flags O_NONBLOCK, VMIN=0, VTIME=0, 
B115200).  The time the data shows up is quantized to 5ms.  Where does 
this 5ms quantization comes from?

Increasing kern.hz to 10000 does not reduce this effect.

Thank you,

Chris