S30V vs S90V

[Vishnu]

I want to make the best kitchen knife possible, and I'm lookin at the CPM's because of all the good things people have said.... But when I look at pages telling the properties of various steels, they tend to talk about toughness and wear resistance. How are these measured? WHat could I expect if I was to use the S90V vs S30V? Is the numerical name at all related to the quality (ie: 30 is better than the 90)?? And are the numbers at all relative when dealing with the carbon steels also?

Any help makin sense of the graphs about toughness and wear resistance would be greatly appreciated!!!

Thanks guys, ahead of time!