Hi, I have dell vostro 3750, with i5-2430m, and gt525m. There was 4gb stock ram, but I have one needless ram 1gb, with same brand, mhz, and etc. spec. I try to add that 1 gb to my laptop, and I feel better performance, mhz changed from 667 to 1333 mhz, windows rating also increased. So this 5 gb is enough, or make 8 gb ram system? Will I feel big difference or something? Hynix ram is good?