4870 crossfire + Antec earthpower 550W + Core I5 750 OCed

[Drfluffy]

Hello guys

Long time reader, but just registered thinking about this dilemma.

I would like to upgrade my rig a lil, adding an extra 4870 in cross fire (it's cheap right now), but I only have a 550W power supply (a good one that definitely deliver 550W)

I overclocked my core I5 750 to 3.2ghz on air and my 4870 is OCed to 4890 specs (but I can drop it)

Currently I am going by this article

http://www.anandtech.com/show/2683/7

where it states a rig with core I7 940 OCed and 4870 x fire has a max power draw of 563W, but I understand core I5 750 OCed

however, in this article the CPU load alone is 437 W, where as in this article

http://www.tomshardware.com/reviews/core-i5-750-overclock,2438-11.html

the total system power of a 4.0GHZ i5 750 is almost half of that above.

Question is, will I be ok for this upgrade?


Moved to PSU forum.

Super Moderator BFG10K.

 

[theAnimal]

Which model PSU do you have? There is no such thing as "Earthpower", and the Earthwatts does not come in a 550W.

 

[Drfluffy]

I just realized that my motherboard is of PCI express 16X/4X configuration and does not support crossfire properly.

Oops.

 

[superccs]

I think you might want to check your specs again on the i5, that should be a ~95W part not 437W part.

I think there is no harm in trying the described setup and see if it works. I can see though that you are most likely approaching your PSU ability, something I think many of us ever approach in our own builds.

From some subtractive calculations between a 4870 and a 4870 CF wattages you can predict that each 4870 is using ~150W of power http://www.anandtech.com/show/2556/22

Thats a C2Q 9770 on a power hungry nforce 790i + 2x HD4870 = 473W total power usage.

I think you can get what you are wanting out of your current 500W PSU, considering your i5 and H55 probably have more conservative power requirements.

 

[evolucion8]

the PCI-E 4x might be an issue in some scenarios, but generally should be enough to get a nice performance boost on the cheap.