the particle code ic currently early beta and this part is some kind of LOD handling. eg: if you're near the Emitter it will emit the full particles, if you go further away from the emitter the particle count is reduced by the distance. Currently it acts very fast so you have to be really near if you want to have the full particle count. In the future I will provide an option to disable the LOD and I will optimize it that LOD will act first at a certain distance.