Netplay actually uses like 20% more CPU than offline, probably due to having to wait for syncing or something. Also, I have the exact same processor and can run Dolphin mostly fine. I used to be able to run Mario Galaxy at around 45 fps; but that was quite a while ago. Mario Kart Wii is probably a no right now, but if texture pooling is ever merged again, it should be possible on that processor.
Source: Experience.
Source: Experience.
