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Enough power

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  • Power Supplies
  • Power
  • Components
Last response: in Components
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March 15, 2011 11:45:36 PM

hi guys.
im trying to assemble this build.

but im not sur eif the power supply im taking is good enough.

Intel Core i7-2600k (will be overclocking)
MSI P67A-GD65 SLI
MSI n580 Twin Frozr II/OC
8gb ddr3 Ripjaws X
1TB SATA drive


so for the power supply

Hec Cougar GX1050w 80+ GOLD (Modular)
PSU link: http://www.cougar-world.de/en/products/power-supply/cou...

is that enough for the system?
esp for the 580

the nvidia site says minimum is 244w so thats 20 amps
the evga site says gtx580 needs 42 amps.

so. my problem is , that PSU is 1050w..
has 6 12v.. but each has only 25 amps.

i only have 1 gtx580.. and might be getting another 1 for sli..
and thats it..

so.. is this enough? ( maximum )
i know its okay for the minimum.. but.. the 42 amp troubles me.


the hec cougar 1050w costs 7300php
should i get cheaper PSU with 750w or 850w but has higher amp in its 12v?

this is the available PSU at my local area..
http://www.pcx.com.ph/index.php/components/power-suppli...

any PSU available there you guys can recommend me..?


More about : power

March 15, 2011 11:49:46 PM

Only 150A?
That power supply will run two GTX580(s) in SLI at load with the CPU overclocked to 4.7GHz and probably still not use the full 1008w.
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March 15, 2011 11:58:00 PM

omnisome said:
Only 150A?
That power supply will run two GTX580(s) in SLI at load with the CPU overclocked to 4.7GHz and still not use the full 1008w.


hello omnisome, thanks for replying.

150amps?

did you combine the 6 12volts ?

ill be using 1 for now, and probably 2 if i sli..

so the psu gives 25a per 12v..

or im just confused..
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March 16, 2011 12:00:05 AM

150A = 1008w
This is the total output that the power supply is capable of. Don't worry.
25A + 25A + 25A + 25A + 25A + 25A = 150A
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March 16, 2011 12:05:38 AM

so.. its totally fine even if i sli 2 gtx 580..

so.. the thing written in nvidia site that 580 needs minimum 20 amps

and evga site wrote the 42 amps for gtx 580 is nothing to worry about?

(cougar = 25amp each 12v)


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a c 289 ) Power supply
March 16, 2011 12:32:19 AM

omnisome said:
150A = 1008w
This is the total output that the power supply is capable of. Don't worry.
25A + 25A + 25A + 25A + 25A + 25A = 150A


WRONG!

Watts = Amps * Volts


On the 12V rails it lists 1008W as the max power, so 1008W divided by 12V is only 84A, thats still quite a bit of power. 6 rails at a max of 25A each does NOT mean that you can add them all up and get 150A off the 12V source for the unit. The rails do not provide power, they just watch and shut down the unit if more than a certain amount tries to flow past them, they all draw from a common source which is almost never capable of feeding them all entirely at the same time.


150A @ 12V would be 1800W of DC power, in north america your household wiring provides 110V nominal to a normal outlet, to get 1800W from an outlet you would need to pull more than 16A from the wall, your average household circuit is only 15A so it would trip every time you loaded it up, there should have been multiple this doesnt make sense moments.


@OP the power requirements for the cards are for the system as a whole, and the PCI-E connectors would be on different 12V rails, as long as you arent using adapters you dont have to worry about the rail limits, they already designed around that, you just need to look at the total power available for the unit's 12V rails which in this case is 1008W(84A)
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March 16, 2011 12:41:50 AM

hello hunter315. thanks for your reply.

i somehow kind of get a little of what youre trying to say..

so..
this power supply is good enough to power the gtx580 and or 2 gtx580 sli?
or it can power the 580 but the 580 cant use its full capacity?

(not going above 25amp) since the wire can only get 25amp.
(confusing myself)


or..

so the hec cougar 1050w is okay?

or

should i get a single rail 12v psu?
if so. which PSU from the site would you recommend
http://www.pcx.com.ph/index.php/components/power-suppli...





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a c 289 ) Power supply
March 16, 2011 12:56:45 AM

Single rail or multi rail really doesnt matter these days so ignore that and only look at the combined power.(ill explain why it doesnt matter farther down)

The PSU has 84A available, a GTX 580 uses about 280W which is about 23A, so two of them would pull about 46-48A, which leaves about 30A(360W) available for the rest of the system which is more than enough, the next most powerful item in the system is the CPU which needs less than 150W(~12A), everything else in the system needs minimal power so that unit has more than enough power for 2 GTX 580s in SLI running at full power with some overclocking.



Now for the reason why the rail splitting doesnt matter.
There are a few customary ways to do it, what i am guessing by their distribution of connectors is that they opted for this.

The CPU gets its own 12V rail for the 8 and 4+4 pin connectors(this used to be mandated in an OLD ATX spec but has long since been dropped but some companies still do it)

One rail feeds the motherboards 24 Pin main connector and some drives, another rail feeds the rest of the molex and sata power connectors

Since there are 6 6+2 pin PCI-E connectors there are likely 2 per rail, this works out pretty perfectly for their rail distribution as an 8 pi PCI-E connector is rated for 150W(12.5A) so two per rail gives you 25A, the max capacity of the rail, now, this is fine as any card that bears the PCI-E logo(the 6990 and the ASUS ARES do NOT bear the logo as they exceed the rules) is not allowed to draw more than 300W of power, it gets 75W from the slot and 225W from the PCI-E pin connectors allowing at least 75W of extra power available to OC with.
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March 16, 2011 1:06:27 AM

hmmmm okay...

so.. for the record..
this hec cougar GX 1050w is good enough.. ?
and i should take it..

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a c 289 ) Power supply
March 16, 2011 1:13:42 AM

HW Secrets did a review of its 700W cousin and they liked it so its a pretty good unit
http://www.hardwaresecrets.com/article/Cougar-GX-700-W-...

The site you linked to doesnt have any better option for high powered units like 850W units, so as long as the price is reasonable i would go for it.
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March 16, 2011 1:25:44 AM

hunter315 said:
HW Secrets did a review of its 700W cousin and they liked it so its a pretty good unit
http://www.hardwaresecrets.com/article/Cougar-GX-700-W-...

The site you linked to doesnt have any better option for high powered units like 850W units, so as long as the price is reasonable i would go for it.



and one last thing.. would the 1050w be safe..?
( no melting wires? or something under heavy load.. )
- been reading reviews / people talking about single rail and multiple.. etc..
and it made me confuse more..


at the site..
there are some 1000w psu..

looking at
this CoolerMaster GX-750 750w 80PLUS for 1/2 price of cougar 1050

Thermaltake GRAND 80+ GOLD 750w same price w/ cougar 1050..

FSP Everest 800w 80PLUS modular for 1/2 price of cougar 1050

Thermaltake LitePower 700w 1/4 price of cougar 1050

men.. the deeper i get, the more confuse on which PSU should i take..





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a b ) Power supply
March 16, 2011 5:03:12 AM

You can use 2 rails or one rail to power a gtx 580.the figure stated by evga is a for the whole system. The one stated by nvidia is just for the card
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a c 289 ) Power supply
March 16, 2011 1:50:34 PM

The Cougar has more power than any of those, and units like the GX 750 certainly shouldnt be used(has major issues with ripple over 60% load) the lite power is a bit lite on power, the FSP everest is an older model, it got discontinued on newegg already so its not high on my list, it was a decent unit but not spectactular, the Thermaltake Grand 750W is a good unit but if its the same price as the cougar i would go for the cougar.
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March 17, 2011 7:33:28 AM

ok thanks guys.. i think ill stick with the hec cougar 1050w.
hopes for the best
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!