Hi, I'm looking to revive an old computer that is really outdated. I already bought and installed a MSI motherboard and an Athlon II X2 250. I chose that in order to use my also old IDE hard drive.. Modern games are unplayable though (even low 1024x768). My PSU has only one 15A 12V rail though. Should I upgrade it to install a Radeon HD 5670??? Should I immediately upgrade the PSU?? Any other graphics card suggestion??