Hello all. I am looking to upgrade the RAM on my MacBook Pro (see signature) from 4 GB to 8 GB, and I wanted to get your advice on it. I am looking at Corsair Vengeance 1600 MHz RAM and have the option of getting either two 4 GB modules or one 8 GB module. Since the price difference is negligible (about 8 USD - 10 %), I thought I'd go for the single module, making it significantly cheaper to upgrade to 16 GB at a later time. What I want to know is: Is the speed difference big enough that I should go for the two 4 GB modules? Or is there another compelling reason to choose the two 4 GB modules over the single 8 GB module? The specifications on the two options are as follows: 2 x 4 GB (part no. CMSX8GX3M2A1600C9): CL9 9-9-9-24 1 x 8 GB (part no. CMSX8GX3M1A1600C10): CL10 10-10-10-27 - Thanks!