500w is a MINIMUM requirement for the 4870 (a GOOD brand such as corsair, antec, P&C). Don't cheap out the psu or you will regret it. You show us antec 430 and the other jewel shyt that will prolly cause you the same problems. If you know your system uses 430 watts don't buy a 430 watts.. it's stupid. You should be aware that the efficiency lowers with aging and heat so don't go under antec 500w and don't go a shyt brand.