4CL vs 5CL

[boise49ers]

I have 4 gigs of G-skill 6400 in my machine listed under my specs. I was going to put 4 more gigs in , but was thinking about putting in 5-5-5-15 instead of the 4-4-4-12. I can get some fairly cheap. If I understand right it will make all the Ram run at 5L. If that is so how much will it effect my performance ? I do not have the memory or cpu overclocked. Just the graphic's card.
Thank you

[NdMk2o1o]

To be honest you might be able to run the CL5 stuff at CL4 I would try that 1st, though there is little real world performance loss from CL4-CL5. In benches you will notice a difference and maybe also lose 1-2 fps in games if that.

[cdawall]

you wont notice and you can always try the new kit at CL4-4-4-12 just cause its rated for CL5 doesn't mean CL4 wont work