Differece between Blender 2.8's camera and world HDRI

Another curiosity. Importing a 150MB hdr (.exr in fact, in this example) as Camera HDRI will really be faster than importing as World HDRI?
Since in both importing modes the original HDRI file is copied to the Blender’s StudioLight folder, and i than suppose that entire file will be put in the RAM for whatever mode it was imported for right?

So besides the behavior of each importing mode, what about the performance? Specially for graphics processing, once i have only an Intel Graphics 4000 laptop, not that much for the RAM consuming, that i have 8GB available.
I use both Windows 10 and Linux (right now, Ubuntu 16.04). Preferring Linux for Blender that is way faster. What the impact in performance between those systems?