Kingston 4g ram for G580

[cpper]

Hi guys

I want to upgrade my G580's 4gb ram with another 4gb stick. Currently the laptop has this stick in it.

My local shop has more options, but two which are in my budget are the Kingston KVR16S11S8/4 and the Kingston KCP316SS8/4 . Looking at the specs, both are identical to my current ram. 

What is the difference between the two ? Which one would be compatible with my G580 ?

[ChrnoPL]

Sell old RAM have the same laptop ram and problems. Buy 2x8GB DDR3 1600MHz its max for this model. 

Any good with unlimited warranty like kingston. Im buying goodram 8GB cuz Poland own and unlimited warranty.

[cpper]

I've read that many people had problems with 16gb, since Lenovo somewhere says that 8gb is max for this model.