Hi, I'm looking to upgrade my hardware, My current GPU is a nVidia GeForce 9100, It sucks for gaming, I'm looking to add another card, a nVidia GeForce GTX 550 Ti, Or 660 Ti, I'm also buying a new power supply, The Only problem, Is my motherboard has olny a PCI Express x16, Please Reply about any problems that i may encounter, Remember: I'm new to upgrading hardware!