Ok I've asked this before but I have a fx-4170 right now and I plan on buying a 7870 I only have a 530 watt powersupply 530 IS enough right? fx-4170 says 125 watt cpu and 7870 reccomended is 500 but i've heard you really dont need as much as it reccomends is this true?
What power supply exactly? The high rating the manufacturers give is taking into account really crummy power supplies( for example a 550 watt with only a 18amp 12v single rail), if you want i can link you some information that can really help you out with power supply choice in the future.
Yes it is enough for a 7870, you are good to go. Here is a good calculator for any future psu requirement questions: http://www.extreme.outervision.com/PSUEngine
http://www.anandtech.com/show/5691/the-retail-radeon-hd-7870-review-his-7870-iceq-turbo-powercolor-pcs-hd7870/4 Here is a power consumption link with a OC 3960X and a 7870, as you can see it only pulls 350 out of the wall. Your 530w is fine for your system for sure, enjoy your 7870.
For the price of a 7870 you can also get a GTX 660, it performs better in some games and worse in others. http://www.anandtech.com/bench/Product/548?vs=660
Check the link and see if the 660 performs better in the games you play or if the 7870 does.
I, too, use this calculator, and it is brilliant. Thanks for the AnandTech link, by the way; I'm in desparate need to upgrade my GPU, currently a GeForce 8800GTS 320MB, and this will be great for comparison!