It simply depends on your RAM design, type and settings, mobo maker , CPU make quality *yes, two exact SAME CPU's will overclock differently* the ability for your PSU to handle higher voltage draw, BIOS flexibility to change settings, ect...ect....

You may reach 4.0ghz with few issues or you may not even be able to overclock at all. Judging from the specs of your hardware, you might be able to get a decent OC but wether or not it will run stable is a whole nother issue entirely. Keep in mind that stock Intel heatsink fan units are crap for overclocking with, so there gonna suggest you spend money on a better HSF unit and likely a better power supply. I'm Freezebyte on both those forums FYI