The reason for pauses is the absence of actual cache in the folder you typed. You see, the game uses a precompiled database of all possible types of materials ("shaders"). It seems that one of the files in your Cache (in Public Documents) is corrupted or missing. You can delete the precompiled shaders, of course. Then The Void automatically compiles a shader for each new combination of a material and a number of light sources you see on the screen, which immediately causes a slowdown. This becomes less of an issue when you play the game long enough, because most combinations are already compiled by the time you get to the later parts of the game. Save for some rarely used materials.
The precompiled database has every (theoretically) possible combination of materials and light sources, even if the material is only used once in one 5-second long cutscene and is lit by 1 Omni Light. It takes from about 10 to 15 hours to compile it all
. A full database in \Users\Public\Documents\My Games\Void\Cache is a around 86 MB.