Any idea, why could this be happening? System process consumes up to 30% CPU, which is unusually, as I have never seen System process consume anything on any machine (including same laptop with Windows 7).
Probably some kind of maintenance running. I wouldn't worry about it unless it stays like that non-stop for a long time or something. It's simply the kernel doing its thing.
I have just figured out that it goes away when I turn off wifi. But it will go back up, when I turn it back on. I guess problem is somehow linked to wifi not reconnecting at standby (other thread).