Another thing is that the integrated graphics will steal memory away from your system. A discrete graphics card has it’s own memory.
The HD 520 and HD 530 Intel graphics are the latest integrated Intel APU solutions (coming with their 6th generation Intel® Core™ i-series Mobile Processors.) It has been asked quite a few times whether SketchUp will run with them, but I haven’t seen anyone report back specifically on them.
I would be interested to know if Intel is doing better with their latest APUs (with regard to OpenGL and SketchUp.)
There is a graphics reporting thread topic around here somewhere.