temporal/spatial count ratio for path tracing.

Hi, can anyone shread some light on how I should setup the spatial sample count/temporal sample count for path tracing still images?

Say I have a still image i want to render out in 256 samples

should i set up as 256 spatial sample x 1 temporal samples?
or should i set up as 16 spatial samples x 16 temporal samples?

both gives similar results in my test