850 Watt PSU enough for 780 ti in sli?

[llWarFacell]

Hallo!

 

First my System specs:

 

Intel Core i7 4770K, ASUS Maximus VI Formula, 16GB G.Skill TridentX 2400mhz, GTX 780 ti EVGA Superclocked, Corsair H100i, Samsung SSD 120 GB 840 Evo, 1x 2TB Seagate 7200rpm HDD, 1x 1TB Seagate 7200rpm, 2x Corsair SP 120's

 

PSU:  850 Watt Corsair RM Series Modular 80+ Gold

 

Case: Corsair 750D

 

And yes, I will be overclocking both CPU and GPU (later even the 2nd 780 ti) and maybe I will build a custom watercooling setup aswell. So will be the Corsair 850 Watt 80+ Gold enough for my upgrade to a second 780 ti ?

[Paralectic]

yes

[Izaya Orihara]

yeah even 750 would be enough. 

[mrogicom]

Yes i think, Linus once run referance 780ti on 700watts

[DoubleY]

yeah even 750 would be enough. 

^This

 

If you got an 80+Gold or Platinum PSU, 750watts would be enough. But if you plan on overclocking anywhere in this rig, I would suggest stepping up to 800 or 850 watts (still 80+ Gold or Platinum) 

[llWarFacell]

^This

 

If you got an 80+Gold or Platinum PSU, 750watts would be enough. But if you plan on overclocking anywhere in this rig, I would suggest stepping up to 800 or 850 watts (still 80+ Gold or Platinum) 

Yeah I will be overclocking for sure, is a 850 watt "just" enough or do I have a little bit of headroom?

[DoubleY]

Yeah I will be overclocking for sure, is a 850 watt "just" enough or do I have a little bit of headroom?

Depends on how far you go. I know that @Lays has a 1050 watt power supply that he gets close to going over the limit it. But maybe that's because he has his CPU at 1.45volts and his 780's at 1.3 volts. He has a 3930K and 2x 780s

[Lays]

Depends on how far you go. I know that @Lays has a 1050 watt power supply that he gets close to going over the limit it. But maybe that's because he has his CPU at 1.45volts and his 780's at 1.3 volts

 

 

Yeah you'd be fine with 850 since you don't have a 2011 chip.  Unless you plan on EXTREME heavy overvolting,  (Like 1.5v per 780 ti and 1.4v+ on the 4770k) you won't hit that 850 watt limit.

[Wyre]

http://www.extreme.outervision.com/psucalculatorlite.jsp

 

I have found this to be a very valuable tool. Just plug in the required hardware and click the 'calculate' button. Running two 780 Ti SLI cards equates to about 700 watts.

[llWarFacell]

Depends on how far you go. I know that @Lays has a 1050 watt power supply that he gets close to going over the limit it. But maybe that's because he has his CPU at 1.45volts and his 780's at 1.3 volts

Oh okey, nah I don't think I can cool 1,45volts with a Corsair H100i haha. I wouldn't go overkill with the overclocking I would say on the CPU anywhere from 1,25 to 1,3 maybe at MAX with the 780 ti the same I mean it's a beast even wihtout overclocking it.

[Mindtrickz]

Easily.

[DoubleY]

Oh okey, nah I don't think I can cool 1,45volts with a Corsair H100i haha. I wouldn't go overkill with the overclocking I would say on the CPU anywhere from 1,25 to 1,3 maybe at MAX with the 780 ti the same I mean it's a beast even wihtout overclocking it.

Then you will be fine with the 850watt

[llWarFacell]

Then you will be fine with the 850watt

Okey thanks a lot!

[llWarFacell]

Easily.

Thanks

[llWarFacell]

http://www.extreme.outervision.com/psucalculatorlite.jsp

 

I have found this to be a very valuable tool. Just plug in the required hardware and click the 'calculate' button. Running two 780 Ti SLI cards equates to about 700 watts.

Thanks thats quite handy

[KieranBrown]

Id recommend a corsair ax860 or ax860i for the efficiency and monitoring in the I model if you want Thai

[VSG]

^This

If you got an 80+Gold or Platinum PSU, 750watts would be enough. But if you plan on overclocking anywhere in this rig, I would suggest stepping up to 800 or 850 watts (still 80+ Gold or Platinum)

What does the PSU efficiency have to do with what it can output?

To OP: Reading your posts in here, you will be fine with 850W.

[DoubleY]

What does the PSU efficiency have to do with what it can output?

750watt 80+ bronze PSU can only output 637.5 watts at max efficiency (around 85%). 80+ Platinum 750watt PSU can output 667 watts at max efficiency. The "750watt" is the maximum input, the question is, how much of that can it re-output after it's been converted from alternating current to direct current.

[WoodenMarker]

What does the PSU efficiency have to do with what it can output?

To OP: Reading your posts in here, you will be fine with 850W.

750watt 80+ bronze PSU can only output 637.5 watts at max efficiency (around 85%). 80+ Platinum 750watt PSU can output 667 watts at max efficiency. 

No, both a 750w bronze and platinum psu will be able to output 750w unless they are crap. 

It's just that higher rated psus tend to be able to output more than what they are labeled and can handle higher loads better. 

[DoubleY]

No, both a 750w bronze and platinum psu will be able to output 750w unless they are crap. 

It's just that higher rated psus tend to be able to output more than what they are labeled and can handle higher loads better. 

Oh. Well thanks for the clarification 

[VSG]

A PSU rated for a certain wattage is guaranteed to provide that many watts, if it doesn't then it is a bad unit or a bad brand. The efficiency only dictates how much it pulls from the wall to provide the wattage to the computer.

As far as some PSUs being able to provide more wattage, sure- some units are under specified but no one should take that for granted. If you want a 1000w unit, for example, no one should gamble and get a 850w unit.