They are both quality PSU's, take the reviews on the EGG with a grain of salt since more people that have problems post a review than people that everything works fine do. Both PSU's got good reviews at respectable techsites.
it will be the SAPPHIRE Radeon HD 7970 OC 3GB 384-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card (11197-01-40G) and i will prob just oc the 7970 to about 1.1-1.2mhz
A single Sapphire Radeon HD 7970 OC 3GB GDDR5 at factory clocks has a power consumption of 219 Watts during gaming.
OC'ing that specific card to 1.1 GHz will increase the card's power consumption to around 240 Watts during gaming.
OC'ing that specific card to 1.2 GHz will most likely require a voltage tweak that will increase the card's power consumption dramatically to around 330 Watts during gaming. For two cards in 2-way CF you're going to be drawing over 650 Watts for just the two video cards.
For comparison two reference clocked (i.e. GPU Core: 925 MHz, Memory: 1375 MHz) Radeon HD 7970 3 GB in 2-way CrossFire mode have a measured power consumption of 375 Watts during gaming. That's just for the two video cards only, measured on the PCIe slots' +3.3V and +12V power lines and the PCIe Supplementary power connectors.
An i5-2500K overclocked to 4.8 GHz will be drawing over 155 Watts when measured at the CPU power connector. That includes the power loss due to the motherboard's CPU power VRM conversion efficiency.
I consider the XFX 850W Core Edition (P1-850S-NLB9) to be the bare minimum for your requirements. Just don't attempt to run FurMark or OCCT GPU3D stress testing because it most likely will trigger the PSU's protection circuit to kick in.
going to go with the xfx anyways more watt and 5yr warranty so thanks @ ko888 and yea i think will run some programs to test if the oc are stable so if the PSU's protection circuit does kick in owell lol.
The Radeon HD 7970 GHz Edition draws more power than the original Radeon HD 7970 925 MHz edition.
Are the graphics cards being overclocked beyond their factory clock speeds? If yes then what clock speeds are you using?