for the ram it in the bios under ram setting in your mb guild the setting should be use ram xmp. that make the board use the 1600 xmp setting on the ram eprom. bottlenecking will happen in games when you toss is aa/faa and high monitors res. when i comes to games each game going to have it own tweeks from the game forums. the best advice people here can give you is to turn down the game video settings from ultra to med if you want higher frame rates.
thank you for the replies....so...there won't be any bottlenecking when i only "overclock" my ram to 1600?? so i don't have to overclock my cpu??
Don't worry about it, my CORSAIR Dominators used to run at 1333 on my Asus Extreme MOBO even though these ram modules are rated for 1600. I just went to BIOS and looked for XMP and set it 1600. If your RAM is rated 1600, then forcing your motherboard to run ram at 1600 is not considered overclocking. I read that the underclocking to 1333 happens due to the intel chip.
Just look for the setting where you can set ram to 1600 automatically, if you don't have it, then you must adjust RAS CAS etc timing acording to your RAM module (and the voltage too to whatever the RAM module works with).
My Corsair Dominators run at 1600 1.65volts, I overclocked my CPU, but left ram as what Corsair boxed them out to be.