Hello everybody, I'm about to upgrade my MacBook Pro mid 2012 A1278 and it has now(before the upgrade) two sticks of 2GB of memory(4GB total). I'm willing to replace one of these 2GB sticks with a 8GB stick and leave the other 2GB on its place (10GB total). Is this a problem for my mac? Some people say it doesn't and a fewer amount of guys say it does. Besides that, I'll replace the HDD for an SSD and also replace the optic drive with another SSD. Thanks!!