Non-buffered rendering causing black screen

[vsub_]

You could say 222mhz is auto.
Lowering can either result in higher or lower game speed and no problems or to have problems(crashing\frezing\out of synch audio and so on...it depends on the game).

I cleared both GoW games on my old pc(p4 2.8ghz,6600gt,1gb ram)with 80 for cpu speed and some frame skipping and it was almost always at 30fps(the game has a mechanism to lower the internal speed automatically of the cpu is running at lower speed)