Anyone else that want to run it could help shed some light on it.This is definitely interesting -- that 2D graphics dropped so considerably. From everything I've been able to discern, that's not an expected result -- the issue that needs to be resolved is in the CPU and relates to accessing system memory. I'd say that if this were an SB2 it might make sense, since the integrated GPU uses system RAM while the dedicated GPU has its own memory. But on an SP3 both 2D and 3D graphics are using system memory -- you'd expect to see the same impact.
Until I see it confirmed elsewhere, I'm going to call this an issue with the graphics driver and something that will be fixed.
IDK perhaps there's some kernel switching in that code.