So this is rather odd, I was testing something else in 4.15P1 and I noticed that occasionally GPU particles would emit rather odd. I wanted to post about it, but didnt have any time.
I just tested the same situation in 4.15P3
And this is Preview3
(CPU on left, GPU on right)
Ignore the brightness change, was to test something else.
the only thing changed here module wise is a spawn module with a rate of 10, and a constant of 20.
the only difference between these two emitters is one being a GPU, and the initial location to have the two next to each-other for comparison.