OC'ing gpu and cpu with low watt psu

[sinkacy]

Hello, I'm upgrading gpu in my comp and I'm seeking some advice.

Current build

Mobo: ASRock 990FX Extreme3
CPU: AMD Phenom II X4 Quad Core 965 Black Edition 3.4GHz
PSU: Corsair CX Series 500W ATX
RAM: G.SKILL DDR3 2x4GB 1600MHz CL9 RipjawsX
GPU: Radeon HD4870
Cpu cooler: Cooler Master Hyper 212 Evo

And I'm buying Sapphire Radeon HD7950 3072MB DDR5/384bit DVI/HDMI/DP PCI-E (950/5000) OC VAPOR-X

I guess the psu wattage is too low for some instensive overclocking so I'm asking how far could I go with oc'ing both cpu and gpu.

Thanks for help

 

[alvine]

http://www.amd.com/us/products/desktop/graphics/7000/7950/Pages/radeon-7950.aspx#2

amd recommend minimum of 500watts so if you overclock either cpu or gpu your system will turn off randomly when under stress the psu will be at peak usage and you're risking frying everything ur psu is connected to
upgrade your psu to 600-650 for safety

 

[C12Friedman]

No upgrade needed. Your system with everything overclocked will not draw more than 375W. You have a good PSU so you don't need to be concerned with overload like you would a low quality PSU. Keep what you have until you're ready to go to X-Fire, you won't hurt anything power wise by overclocking your system as is.
Hope it helps
Edit: Note that AMD does not specify whether the system is overclocked or not - doesn't matter as far as their recommendation