Deep memory

I'm about to buy a laptop. I have the final choice between 2 PCs. One has 4096mb RAM with a frequency of 800MHz RAM. The second also 4096mb RAM but a 667MHZ frequency.

I got a little information on the net. And I saw that the PC gave more performance over the frequency of the RAM is high. Is that correct?
But what is the difference is really noticeable?? Because ultimately the one who has a lower frequency interrelated more of these other characteristics. (16.4 screen, keypad, graphics card a little bigger)

Thank you for your help.

The frequency of memory has nothing to do: it is the frequency of Proco and fsb that are important.
If you have a amd with a fsb to 400 the ram it into 667 or 800 transmit the data at the same speed.
As the frequency of the ram is not inferior to you fsb not see any difference.
For against modern chips with the number of bars is important: always an even number .. 2, 4, 6 never 1, 3, 5!

in this case, I think it would be appropriate to us the characteristics of 2 machines or their links ... to advise you at best