how much psu wattage do i need for a new Graphics Card?

[OneEyeWilly11]

how much psu wattage do i need?

I have an hp envy h8-1534 desktop with an AMD fx-6120 processor, 1 hdd, 10gb ram. I want to put in a radeon 7850 gpu. I used newegg's psu calculator and it said 426W for the whole system. my stock psu is 460W. Would i be okay or do i need to get a corsair 500 or 600 watt psu?

 

[aevm]

AMD's official recommendation is 500W, but they do say "Your system may require more or less power."
http://www.amd.com/uk/products/desktop/graphics/7000/7850/Pages/radeon-7850.aspx

I think you'll be OK, since you have a single hdd. Try with the PSU you already have. If it's not enough you'll know - you will get crashes while playing games.

 

[Typolo]

The 460 should be fine, but is probably inefficient since it came in a prebuilt system. Plus if is older, it may have experienced capacitor aging and can not supply the full 460 watts anymore.
The corsair cx500 should be plenty of power, reliable and efficient

 

[Vic 40]

I think you'll be OK. Try with the PSU you already have. If it's not enough you'll know - you will get crashes while playing games.

I agree with aevm.