Can I change the power supply of the dell xps studio 9000?

The Studio XPS 9000 only comes with a 475W power supply specifications still for the ATI Radeon HD 5870 (which is one of the options) require a min 500w and I want to upgrade my graphics card and most will know that 475W limit myself, so it is posible to replace it or if there is any reason, if the motherboard .. etc. I can not?

I would be surprised if a source of 475W comes with a 5870. This just asking for trouble. Theoretically it would still work well, but I would not want to test this assumption with the card a high price. It depends on what other components you use. Replacing the power supply is easy and they are all basically universal. The quality of the offer has a great influence however. Within Corsair's 600w, for example, will be significantly better and better power than a budget brand 600w.

XPS 9000 Review