Can my PC handle this Card?

I have a similar PC as yours, but just that it's a generation older, the Dell XPS 8300 (specs at my signature). You will need a new PSU, I don't think the 460 watt PSU that comes with the PC will work well with the HD 7870. Any 500 - 600 watts power supply should work fine like sam1911 listed.
 


You are totally wrong. Seasonic makes one of the best PSUs on the market. Here's a review from jonnyguru's website, he gives it 9.7/10. Seasonic is one of the only companies that makes their own PSUs, unlike others they rely on other companies to make the PSUs for them.
 
No way I am saying Seasonic is Bad but the one he listed has low amp on 12 volt rail thats all .peace :)
 


Oh. I don't think it will make a difference at all, since the HD 7870 doesn't use that much power. But neither PSU are fine.