Yes, make sure it's of decent quality. You don't have to buy the most expensive, or very high power, but it should be a reputable brand. EVGA, Corsair, and Antec are examples of power supplies that would be better choices than the type you have now. Also make sure that any power supply you pick has the 6 pin or 6+2 pin pci-ex connector that the videocard you pick needs. If the card you want needs an 8 pin, for example, the power supply should have a 6+2 pin pci-ex connector on it.