Your friends system is not compatible with g.skill ripjaw memory module the maximum it can support is 1333 Mhz while g.skill is 1600 Mhz.
Since your friend will be having discrete GPU try it with 4gb if he is not satisfied with performance he can always opt for another 4GB memory module of same brand and same type.
Since your friend will be having discrete GPU try it with 4gb if he is not satisfied with performance he can always opt for another 4GB memory module of same brand and same type.