Testing h5py boolean vs uint8 write speed

March 29, 2017

When testing why nidaqmx-python was taking so long to read data and write to HDF5, we benchmarked h5py boolean write speed: h5py_write_speed.py.

h5py write speed benchmark

dtype	write time [sec]
ndarray bool	6.6e-4
list of bool > Numpy uint8	3.2e-2
list of bool	1.7e-2

The penalty in writing boolean arrays from lists to HDF5 via h5py is the conversion from list to Numpy array implicit in writing with h5py.

The order 10 ms h5py boolean list/array write time was not the issue, rather it was the synchronous reading of digital IO that was jamming up the system.