I am hesitant to buy a Radeon HD 5850 because.... Right now I am using a Radeon Hd 4850, I was hoping to upgrade to an HD 5850, but I am afriad that my C2Q Q9400 2.66 GHz @ 2.66 GHz would bottleneck the new GPU so severely, that I may actually get less performance than I am with my current graphics card. I've been told that with or without a bottleneck, I should still get a huge performance boost by upgrading from my HD 4850 to an HD 5850. My system specs include the following. Core 2 Quad Q9400 2.66 GHz @ 2.66 GHz. 6GB of DDR2 800MHz RAM. Radeon HD 4850 (512 MB) Foxconn G33 motherboard (I have a GIGABYTE GA-EP45-UD3P but I haven't installed it yet) Corsair TX750 750W PSU. DVD drive. m-ATX case (I have a coolermaster HAF 932 full tower case, but it hasn't been installed) Stock air coolers.