So i'm pretty sure i'm getting a Sapphire Radeon HD 6870 for Christmas and I was wondering whether I could wait on getting a new psu till later, (month tops), I currently have a 460W Dell PSU, and I think what they recommend is 500W, but to be safe I was going to get a 650W.
Is it 100% necessary for me to get a new psu first? or can I wait a little?
The 460 watts Dell PSU will not cut it. Cheaply made with mediocre quality components. Don't risk the components of your PC with this PSU. With the new 6870 you will need a good quality 650 watts PSU (Corsair).