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Will this 550w be enough?

Last response: in Components
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June 15, 2012 7:00:23 PM

The power supply is a CIT 550W (from ebuyer.com) and i believe it has a 16Amp 12V, not really sure if its right.

The rest of the components going into the build is:
ASUS P8Z77-V PRO
Intel i5 3570K
ASUS GTX 670 Top edition
16GB (4x4) Corsair Vengeance 1600Mhz
ASUS Xonar D2X sound card
Corsair H100
Samsung 830 128GB
1TB WD black/Samsung equivalent
500GB WD/Samsung
An optical drive of some sort
A maximum of 10 LED fans (case is a 600T)

I calculated all these components using this online PSU calculator and it came out with, i think, 523W-Recommended.


Will it be enough?
If not what is that CIT psu lacking of?

More about : 550w

a c 111 ) Power supply
a b Ĉ ASUS
June 15, 2012 7:05:51 PM

I would not even try running that system with an unknown psu brand.
June 15, 2012 8:05:31 PM

Seriously, any cheap PSU company like that is NOT good, if will wreck your system. Think about, whats the point in getting a great rig like the one your getting, but then cheaping out on the PSU? Don't. And get a 650w just to be on the safe side
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a c 1203 ) Power supply
a b Ĉ ASUS
June 15, 2012 8:34:20 PM

An ASUS GeForce GTX 670 Direct CU II TOP (GTX670-DC2T-2GD5) can draw up to 210 Watts under maximum power draw.

During gaming it will be in the 200 Watt to 205 Watt range.

The power supply's combined +12 Volt continuous current rating should be at least 33 Amps or greater.

Your CIT 550W will have a combined +12 Volt continuous current rating that is less than 33 Amps. More likely 28 Amps or less. It only has one 6-pin PCI Express Supplementary power connector which is a good indication that it doesn't have sufficient +12V capacity to properly power your system with a graphics card like the ASUS GTX670-DC2T-2GD5 that requires two 6-pin PCI Express supplementary power connectors.
June 16, 2012 1:07:28 AM

Very nice explanation there ko888. Thank you.
What would actually happen if i tried to use that psu with the components above and ofcourse converting one molex into a 6pin to power the graphics card?
Would the psu blow up or the components short circuit? :s
a b ) Power supply
a b Ĉ ASUS
June 16, 2012 1:24:56 AM

wrenaudrey said:
Would the psu blow up or the components short circuit? :s

If components are designed properly, either an under-voltage lock-out gets tripped and the affected components shut down potentially crashing or turning off the system or the PSU's over-current lock-out trips and the PSU shuts down or the PSU loses "PWR_GOOD" and the motherboard goes into reset state.

Worst case, the PSU blows up.

Worst of worst cases, the PSU blows up and takes a few other components with it. However, most PSUs and many devices are designed to guard against that at least to some extent such as crowbar circuitry to forcibly trip the PSU's over-current protection, blow the PSU's fuse or hopefully at least blow the PSU itself before anything worse happens.
a c 1203 ) Power supply
a b Ĉ ASUS
June 16, 2012 3:02:53 AM

wrenaudrey said:
Very nice explanation there ko888. Thank you.
What would actually happen if i tried to use that psu with the components above and ofcourse converting one molex into a 6pin to power the graphics card?
Would the psu blow up or the components short circuit? :s

If the PSU is unable to supply enough power to the graphics card the graphics card may just display a black screen when it switches over to 3D rendering mode (i.e. gaming or other applications that require graphics acceleration).

If the power supply lacks the proper OCP (Over Current Protection) or OPP (Over Power Protection) circuits anything can happen from power supply failure along with damage to the motherboard and/or graphics card and/or hard disk drive, etc.
a c 126 ) Power supply
a b Ĉ ASUS
June 16, 2012 3:22:53 AM

The short version of all that is "Don't do it!" Don't risk your system on a cheap PSU-shaped object. A quality modern PSU has full range active PFC and some level of 80+ certification for efficiency. Seasonic, Antec, Corsair, XFX, and Enermax/LEPA are among the better brands. FSP has produced some good ones lately (e.g. Aurum Gold), and even Rosewill has been shedding its reputation for producing junk. Sites like hardwaresecrets, jonnyguru, and hardocp have competent technical reviews (i.e. including load testing up to 100% of claimed spec, waveform analysis, etc.) of PSUs, and other information about how they work.
June 16, 2012 5:59:37 PM

How about this this OCZ 850W http://www.ebuyer.com/265709-ocz-zx-series-850w-80-gold...
Any good? Is it like Antec, Corsair, etc.?

And am i right to say that the amperes on the +12V is the most important on a psu?
So why do most people say that this Antec-
http://www.ebuyer.com/246671-antec-850w-high-current-pr...

that has 40A on the +12V is better than these Corsair 850W-
http://www.ebuyer.com/227503-corsair-850w-ax850-modular...
http://www.ebuyer.com/164951-corsair-850w-hx-modular-ps...

that has 70A on the +12V rail?
a c 1203 ) Power supply
a b Ĉ ASUS
June 16, 2012 6:21:06 PM

wrenaudrey said:
How about this this OCZ 850W http://www.ebuyer.com/265709-ocz-zx-series-850w-80-gold...
Any good? Is it like Antec, Corsair, etc.?

And am i right to say that the amperes on the +12V is the most important on a psu?
So why do most people say that this Antec-
http://www.ebuyer.com/246671-antec-850w-high-current-pr...

that has 40A on the +12V is better than these Corsair 850W-
http://www.ebuyer.com/227503-corsair-850w-ax850-modular...
http://www.ebuyer.com/164951-corsair-850w-hx-modular-ps...

that has 70A on the +12V rail?

For a modern power supply unit the combined +12 Volt continuous current rating of the power supply is the most important because modern systems draw the majority of their power from the +12V rail(s).

All of the power supplies you've listed have a combined +12 Volt continuous current rating of 70 Amps.

The Antec High Current Pro 850W (HCP-850) is different in that it has four virtual +12V rails with each virtual +12V rail protected by its own OCP (Over Current Protection) circuit for safety reasons whereas the other power supplies in your list all use a single +12V rail.

The OCZ ZX Series 850W (OCZ-ZX850W) is a very good power supply unit.

Are you looking to run two or three GeForce GTX 670 in SLI mode? Just asking because you're looking at 850 Watt power supplies.
June 16, 2012 7:04:50 PM

ko888 said:
For a modern power supply unit the combined +12 Volt continuous current rating of the power supply is the most important because modern systems draw the majority of their power from the +12V rail(s).

All of the power supplies you've listed have a combined +12 Volt continuous current rating of 70 Amps.

The Antec High Current Pro 850W (HCP-850) is different in that it has four virtual +12V rails with each virtual +12V rail protected by its own OCP (Over Current Protection) circuit for safety reasons whereas the other power supplies in your list all use a single +12V rail.

The OCZ ZX Series 850W (OCZ-ZX850W) is a very good power supply unit.

Are you looking to run two or three GeForce GTX 670 in SLI mode? Just asking because you're looking at 850 Watt power supplies.


So you're saying that the HCP-850 has a 70A +12V rail? But on the specs in that link i provided, it only shows 40A :??: 
But if you're saying that it has 4 virtual +12V rails, does that mean that it has a total of 160A in +12V rails?

That OCZ-ZX850W, is it good enough? I mean, would it be better off for me to get an Antec or a Corsair one?

And about SLI, not really..yet, but maybe, eventually in the future.
In SLI prespective, is 850W enough?
And is there anything wrong with going with a 850W psu when you only need around a max of 550-650W?
a c 1203 ) Power supply
a b Ĉ ASUS
June 16, 2012 7:37:23 PM

wrenaudrey said:
So you're saying that the HCP-850 has a 70A +12V rail? But on the specs in that link i provided, it only shows 40A :??: 
But if you're saying that it has 4 virtual +12V rails, does that mean that it has a total of 160A in +12V rails?

That OCZ-ZX850W, is it good enough? I mean, would it be better off for me to get an Antec or a Corsair one?

And about SLI, not really..yet, but maybe, eventually in the future.
In SLI prespective, is 850W enough?
And is there anything wrong with going with a 850W psu when you only need around a max of 550-650W?

The Antec High Current Pro 850W (HCP-850) has four virtual +12V rails with each rail limited to a maximum output current of 40 Amps. This doesn't mean that you can add up the the four 40 Amp values to get 160 Amps because it doesn't work that way. Its maximum combined +12 Volt continuous current rating cannot exceed 70 Amps from all four +12V rails at any point in time since that is all that the power supply is capable of delivering.

For example, if you're drawing 40 Amps on one of the +12V rails that leaves a remainder of 30 Amps that can be split over the remaining one, two or three +12V rails in use.

The OCZ ZX Series 850W (OCZ-ZX850W) is more than sufficient for your system configuration.

All of the power supplies you've listed are capable of powering your system configuration with two ASUS GeForce GTX 670 Direct CU II TOP (GTX670-DC2T-2GD5) in 2-way SLI mode.

There is nothing wrong in going with the 850 Watt PSU. It just gives you spare capacity to handle future upgrades like SLI.
a c 126 ) Power supply
a b Ĉ ASUS
June 16, 2012 8:00:49 PM

PSUs tend to be more efficient when operating in the middle of their ranges, i.e. 40%-60% load. Considering that a PC is idle much of the time, or doing things other than gaming, an oversized PSU that is only providing 10% of its maximum output will actually draw more power from the wall than a smaller PSU where that number might be 25%. Get a PSU big enough for your realistically anticipated needs, but anything substantially bigger than that will waste power at low loads that will just add to your electric bill. A pair of GTX680 cards (GTX670s are not on their list yet) with an i5-3570K needs <600W according to http://www.extreme.outervision.com/PSUEngine so getting an 850W PSU will do nothing more than cost you money month after month on your bill.

Edit: PSUs lose efficiency at the low end more quickly than they do at the high end; consider that an 80+ Gold PSU is still 87% efficient at 100% load; at 10% it has probably dropped down to 75%. A 650W PSU would be a good size for you.
June 16, 2012 8:42:25 PM

Thanks alot ko888, all my questions are answered.
!