Need info about determining server's speed

Hi

I'm new to this subject, so let's say I want to target mainly American surfers, and I have server A in the u.s., is it always true that the lowest ping server is the fastest server?
So if A pinging B is 30 milsecs and A pinging C is 40 milisecs so B is faster?
Are ther more parametrs that I'm not aware of?

 

 

 

 

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