I have a Intel HD Graphics 4000. I have a 15" non-retina display model. It comes standard with a NVIDIA GeForce GT 650M with 512MB of GDDR5 memory and automatic graphics switching.
It's not only the extruded objects that mess up my render speed (because they are only used for a small part of the video) I believe it is also Timewarp maybe? I use a lot of timewarp and that could be a major factor, but I don't know entirely, I'm just asking questions.