For loop, Performance

i have a few question regarding for loops, if you can point me to some sources or answer me here directly I would appreciate it.

The question is:

    for(int i=0;i<List.Count();i++)
{
 //some code
}

is this FASTER or SLOWER comparing to this:

int count = list.Count();

for(int i=0;i<count;i++)
    {
     //some code
    }

and is it the same if I use Dictionatry.Count() or List.Count(). Does it always call the Count() function when it iterates in the for loop im kinda confused about this, do i gain any performance boosts?