So, after upgrading the RAM in my Lenovo ThinkPad T-420 I thought I'd get faster performance. But even with two 8GB sticks?....it's running even SLOWER?! Is there something I've done wrong? It's got a 320GB 7200RPM hard drive....and it's running F30. Funny thing is? .....before the upgrade it had just 8GB of RAM (two 4GB sticks) and seemed to run smoother and faster. Is there anything I can check to find out what the problem could be?