Hi everyone! I have a Dell Inspiron 545 with a Intel Core 2 Quad CPU Q8400 @ 2.66GHz, a 300W power supply unit and a ATI Radeon HD 4300/4500 Series that I would like to change. My motherboard doesn't allow me to put in it a dual slot graphic card (I have the wireless card under the PCIe x16 and I would have to change it, but this isn't a big problem) and a graphic card longer than 7 inches, since there are the SATA connectors for the hard disks. Which graphic card I should buy to improve my pc graphic perfomance for gaming? I have a 1920x1080 monitor but I can reduce the resolution. I know I should buy something like GeForce 550ti to really improve the performance but this kind of card doesn't suit in my pc. With my current graphic card a 1GB card will be a good improvement yet. Thanks!