I have a Compaq CPU with a 250 watt power supply. I have had A LOT of problems trying to upgrade my power supply because of the size of the Compaq. It must be a propietary size or something!!! My question is what is the best graphics card upgrade (nvidia) without having to change my power supply??? I have been looking at the "NEW NVIDIA GeForce FX 5200 128MB AGP Video Card DVI/TV" and the "Brand New! Nvidia Geforce FX5500 256MB AGP 8X w/DVI OUT" and the "NEW nVIDIA GeForce FX5600 AGP 8X 256MB Video Card v21" Can I run any of these with a 250 watt supply? Which is best?? Thanks!!!