Particle Effects spawn less particles inside the engine

Hi,
the particle systems, for example the p-fire in the content is not shown right inside the unreal engine viewport. There are less flames/particles spawned, so it looks like the fire would not burn constantly.
In cascade, it is the same. I noticed, that the numbers bottom right in the viewport, are very low. You can see it in the picture.

Does anybody have an idea what I can change in the settings of Unreal Engine to solve this problem?
Otherwise it is difficult to create particle systems, without knowing, how it looks.
When I export it to an windows exe-file, everything is OK, the fire looks right.
My laptop uses a skylake i5, 6200U processor (duo-core, 2.3 GHz) and the intel graphics 520. That’s maybe not perfect, but the computer is not at its limit when working in unreal engine, so it shouldn’t produce problems.
Thank you for your help.

check your editor scalability settings:
link text