Question on BIOS options

[Silent Knight]

So i'm overclocking my i3 530 on the Asus P7P55D mainboard.In the BIOS,there are 2 options:CPU Differential Amplitude and Clock Skew.Can anyone tell me what are they and how can they affect the overclocking?Because they're describe as "Difference value may enhance BCLK OC ability".

I'm currently running at 230MHz BCLK with CDA at 900mV and CS at 300ps,and i'm planning on pushing it to 237MHz,giving the CPU clock of 5214MHz.Thanks in advance.