I have the following custom pc and I'm looking for a good graphics card that will not bottleneck my system. My processor is an Intel Core i3 2130, which is 3.4 ghz dual-core hyper-threaded. I have 4 GB ddr3 ram, a good 550 watt power supply, and a decent motherboard. I do not plan to sli or crossfire. Please answer with suggestions for nvidia and amd radeon.