Quick question about Core/Memory Clock Frequency

[ToXiCRaGE]

I trying to o/c my video card and trying to live up to the specs of some tested combinations. When someone says for exapmle 125/150Mhz which one of those # is core clock and which is frequancy. Can someone also tell me if a standard fan on a v.card chip is good enough to push it a bit further and how can i run the demo in Q2 to test frame rate in that game - what do i type in the console of Q2?

Many Thx!