The 755 does not support ANY AMD processor. The 755 video slot is 1 slot wide. There are no dual slot 755 models. So none of what you want to do works ever. Power supply can be upgraded but the cards that fit do not need more than the 305W unit in the mini tower. Smaller cases cannot use a standard power supply and have no upgrades. [IMAGE]DUAL SLOT CARDS DO NOT FIT
Hello, I'm planning to upgrade my OptiPlex 755. My current specifications are as follows: CPU - Intel Core2 Duo E6550 @ 2.33GHz  GPU - NVIDIA GT 240 RAM - 6GB DDR2   My upgrade will be: CPU - AMD Athlon 3000G GPU - NVIDIA GTX 970   Would this work with the OptiPlex 755? If not, what would be a suitable upgrade for these parts?
OptiPlex 755 upgrade