Enough power?

[Kenny nguyen]

Is a corsair AX860i PSU enough power for this build:

i7-4790k

Asus Maximus hero 7 motherboard 

16 GB of Kingston HyperX fury ram

2x MSI GeForce GTX970

2x 1 TB WD black HDD

and some fans 

[Godlygamer23]

That's plenty of power. You could step it down to 750 or even 650 watts.

[EarthboundHero]

Way more than enough, you only need a 750W PSU at most.

[FueledByBacon]

That's plenty of power. You could step it down to 750 or even 650 watts.

750 yes, 650 no. Most 650s aren't going to have much headroom with that configuration if they even hit the amperage requirements for dual 28 amp cards (no OC), add the CPU and you're cutting it really close.

[Godlygamer23]

750 yes, 650 no. Most 650s aren't going to have much headroom with that configuration if they even hit the amperage requirements.

I beg to differ. http://www.techspot.com/review/898-geforce-gtx-970-sli-4k-gaming/page6.html

[FueledByBacon]

I beg to differ. http://www.techspot.com/review/898-geforce-gtx-970-sli-4k-gaming/page6.html

Assume gold rated as that seems to be the average now, 87% is 565 watts, 360 is eaten up by the GPU's plus the CPU during stress tests which would eat up another 65 - 70w for a total of around 439 - 440w which is around 75 - 80% of the total power provided by the unit after calculating in its efficiency.

I and many others wouldn't be too happy with that when for another $10 - $20 you could go up to a 750w and have absolutely nothing to worry about, yes it will work with 650 but in my personal opinion and many others you ask its a little too far out of the 60 - 65% efficiency range.

Source: www.guru3d.com/articles-pages/geforce-gtx-970-sli-review,4.html

[quan289]

amperage requirements for dual 28 amp cards (no OC)

 

28A on the 12v is 336w. A single 970 is not a 28A card. That 28A recommendation for a single card you had seen is for the entire computer in which that recommendation has the same amperage rating as some ~400w PSUs such as the Antec Earthwatt Green 380w.

 

Assume gold rated as that seems to be the average now, 87% is 565 watts, 360 is eaten up by the GPU's plus the CPU during stress tests which would eat up another 65 - 70w for a total of around 439 - 440w which is around 75 - 80% of the total power provided by the unit after calculating in its efficiency.

I and many others wouldn't be too happy with that when for another $10 - $20 you could go up to a 750w and have absolutely nothing to worry about, yes it will work with 650 but in my personal opinion and many others you ask its a little too far out of the 60 - 65% efficiency range.

Source: www.guru3d.com/articles-pages/geforce-gtx-970-sli-review,4.html

 

A proper PSU will be rated at DC power - not AC power. Whether if it is Gold or Bronze, a 650w PSU will supply 650wDC for the component. The difference between Gold and Bronze is that, Gold will draw around ~750wAC at 100% load from the wall, while the Bronze will draw ~790wAC.

 

In the benchmark you had linked to, the "system Wattage with GPU in FULL Stress" is 439wAC, with an Sandybridge-E i7 3960x oced to 4.6GHz. This is being powered by an Titanium efficient PSU AX1500i, so that's around 400wDC. If that testing system had a Haswell i5, the power draw will be lower than even that. As such, it will still be in your 60~65% load range that you had mentioned.

[head5ooter]

That is plenty power, i say get a power supply that suits your needs a bit more (something like a 750 watt PSU) and use the extra money for a better graphics card (just mah opinion)