1050w sufficient for my SLI build?

[Rangoon]

I just ran the calculator....

( http://extreme.outervision.com/PSUEngine )

and it told me 854W required, but I estimated some components and want some headroom. But here is the basic setup:

water cooled, maybe two radiators?
i5 2500K hopefully OC to 4.8GHz
8GB DDR3
2 x GTX 580 3GB
1 SSD
1 10,000RPM velociraptor
1 7200RPM caviar black
a few optical drives
1 sound card

I know I need to get more specific soon, but for now I'm trying to massage things into place. Does that seem like a good ballpark number? 854 watts? I am hoping that the Corsair 1050W pro series will be sufficient.

Thanks!

 

[Zap]

Will be fine.

 

[TakeNoPrisoners]

I wouldn't go for an extreme overclock on the GPUs but other then that you can get away with a lot.

 

[Rangoon]

I wouldn't go for an extreme overclock on the GPUs but other then that you can get away with a lot.

You mean in terms of power available? I was hoping to push a couple of GTX 580s to around 900. Would you consider that extreme? I've heard of people getting a good bit higher than 900, but it's still, what...almost 20% That is a lot, but do you think it'll still be enough power?

 

[lehtv]

At stock 580 SLI uses 500W, less than half of the capacity - add 200W for the CPU and the rest, and you still have about 150W headroom for overclocking before you reach 80% capacity at full load.

 

[The Boston Dangler]

your power supply choice is rated for 87.5A at 12V...more than enough. that extreme calculator has never been very good, and that guy saying you can't oc the video cards has no idea what he's talking about. search for "(your part name) tdp" to find how much power it consumes in watts, then divide by 12 volts to find the amperage.

stock gtx 580 = 244W = 20.33A x 12V
max oc = about 380W = 31.66A x 12V

stock i5-2500k = 95W = 7.91A
max oc = about 180W = 15A

32
+32
+15
-----
79 Amps at 12V. call it 80. the rest of the computer takes very little juice.
87.5 Amps at 12V rated output of Corsair 1050W.

ignore the total wattage listed by most power supplies, and look at the "+12V" rating. crappy power supplies will pump up the total wattage claimed with high 3 and 5 volt ratings, which are completely useless. some POS rosewill 1000W has the same 12V capacity as my 650W. 1000 is better than 650, right? wrong. if you needed a lot of power, didn't check the 12V rating and just went by "wattage" you'd have a fried power supply at very least.

 

[Ben90]

Interestingly enough, using the above numbers and a more realistic value for the Cpu/System, it pushes the PS just a little too much.

 

[OVerLoRDI]

Interestingly enough, using the above numbers and a more realistic value for the Cpu/System, it pushes the PS just a little too much.

I'm still surprised by Idontcare's numbers from his little experiment. 300+ watts for a 4.8ghz Sandy Bridge.. Seems like the motherboard would melt

 

[boxleitnerb]

This is only if you increase voltage to get the last MHz. My system with a 2600K@4,3@1.29V with 2 GTX580 3GB uses 115W in idle and around 700W maximum under load. Absolute maximum.

 

[Rangoon]

This is only if you increase voltage to get the last MHz. My system with a 2600K@4,3@1.29V with 2 GTX580 3GB uses 115W in idle and around 700W maximum under load. Absolute maximum.

So, going up to maybe 1.4v max (on water, and just from what I've read around the web), how much would that increase overall wattage under load? I think they come stock at 1.3v, right?

 

[boxleitnerb]

I would not increase the voltage to 1.4V on a 32nm CPU 24/7. Apart from being very inefficient, this would probably lessen the lifespan of your CPU. I read in a review that 1.44V and 5GHz increased the power consumption by about 100W compared to stock. I think stock voltage is around 1.2V.