Which memory core speed with CPU AMD 965 ?

[metapren]

Hi everyone !

For start, excuse my english..
..and i also suck in hardware matching, not great in computers in general..
Have a problem, not really sure its for this sub category or CPU ?!
Ok, so im buying a new computer and one thing bothers me. If i take CPU AMD Phenom II X4 965 at 3,4 GHz on Gigabyte GA-MA790FXT-UD5P board (which supports DDR3 1600 Mhz and below)..
.. At what core speed should memory module be to match the CPU capability/capacity? (not sure how to express myself, told you im a noob
Will it use full capacity at 1600 Mhz ??
I plan buying 2 x 2 Gb Kingmax (which is on the motherboard memory support list)

 

[roonj]

Not sure where to read this data from but originaly the am3 chips memory controller was tuned to 1333mhz. I think you have to read it in the white papers from amd to be sure, better yet someone with a link to this info might post it here.
Once you exceeded the 1333 speed setting the gains are limited.

 

[metapren]

Thanx roonj !

So basically, 1600 Mhz memories are just for overclocking ?