ok, lemme preface this by saying that all these topics blow my mind so i must be an ultra noob. ive installed a couple vid cards on my comp before but thats the extent of my hardware expereience. im looking to install another new vid card on my comp but im gonna need a new power supply seeing as my current is only 225w and the card i want is minimum 420. im not sure how to find out what kind of power supply i need. ATX? BTX? SFX? ATX12v? i have no clue where to begin. i have a dell optiplex gx270, im upgrading my geforce fx 5200 (dont laugh) to one of the new ati x1600 pros. a little help would go a long way. thanks for your time.