Hi there!
I think I have an idea as to what might be going on. You GPU is integrated into your CPU, and uses shared system memory (your RAM). KSA's current architecture relies heavily on video memory (VRAM) which is most effective from dedicated GPUs. Shared memory like in your case can still be used but the speeds are going to be reduced which is probably the cause of your frame rate.
There's talk from the devs on new ways of handling the textures in-game which may help with integrated graphics systems like yours, but that's down the road with no ETA yet.