Nope, if they are working happily together, keep them going. I only suggested keeping the one set because of possible compatibility issues and the fact that the 1600MHz has better timings - seems there aren't compatibility issues so you should be okay running 12GB
Thanx mate! you're like a God to me lol
one last question please...you say that the 1600MHz has better timings...but it has 8-8-8-24...it's lower than the other ram 9-9-9-24...Can you please enlighten me?