The thing to remember is that its going to be shared memory, and most IGP's memory access can be limited in quantity. That being said, the IGP doesn't care a bit when you are loading a large spreadsheet or what-not. This requires no shaders and generally won't even have a measurable impact on your CPU. If you are worried about it, set your IGP memory down to 128 MB.
16-55/28, 23/2, 56/1.2, 18-135, 100-400, 1.4x t/c.
Minolta MC 50/1.4, MD 135/2.8