I recently upgraded my RAM from 4GB to 12GB. To be exact, I had 2X2GB RAM stcks and added another 2X4GB sticks. Now the thing is my Motherboard has 4 DIMM slots for RAM and 2 PCI-E X16 slots. I mention this because I have 2 white DIMM slots and 2 blue DIMM slots, and the PCI-E slots are Blue , so when I only had 4GB RAM I left the 2 white slots open and inserted the 2X2GB in the blue slots. Not shure if this wil help you in solving the problem but I'm just being thurough. NOw for the problem. I do high-end video creation and 3D animation using Adobe After Affects and 3DS Max so, as you may know, serious gear is needed, so 4GB was killing me so I went ou ant bought 8GB RAM with matching speed(1333mhz) and brand(Mushkin) as the 4GB, I did this trying to avoid collaboration erros, but I now have the problem that my computer is much slower than it was before I inserted the 8GB ram. All my programs is unbelievably slugish and unpracticle. Note that windows registers that 12GB is installed. What can I do? Is there some special setup I did not do? Should I flash the BIOS?