Need PSU - i5-3570K, 7950 CF

[icu222much]

I have selected my components, but am unsure how much power my system needs. I heard that it is very important to get a quality PSU as a cheaper one may damage your system. I plan to Crossfire my 7950s, and overclock my CPU and GPU to within safety temperatures. After doing some research on other builds similar to mine, I noticed that most people got PSUs around the 850w to 950w range. I wasn't sure if they also considered overclocking. In the future, I will also add on an additional one or two more 7200RPM hard drive.

I heard alot of good things about Corsair PSUs so I was thinking about getting a Corsair TX850. Would that provide enough power?

i5-3570k
CM Hyper 212 Evo
Gigabyte 7950 Crossfire
ASRock Z77 Extreme4
GSkill Ripjaw 2x8GB
WD Caviar Black 1TB
Crucial M4 128GB
Rosewill Thor V2

 

[crazymonkeyzero]

Hi and welcome to the forum.


To answer your question. Yes, 850W is more than enough to power your crossfire setup with comfortable headroom to spare, in fact, I believe can get by with a good quality 650w. Here's a nice site where you can check how much power you need for your setup, including overclocks.

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

I'd probably stay in the 700w range to be "comfortable" with the overclock. Corsair does make some good psus, especially their HX and AX series which are also modular.

For the price of $100 this Rosewill Capstone 750 is currently a steal.

http://www.newegg.com/Product/Produc...82E16817182073

Here are some other good ones that will also fit the bill, but are a bit more pricey:
corsair hx 750
http://www.newegg.com/Product/Produc...82E16817139010

seasonic x750
http://www.newegg.com/Product/Produc...82E16817151087

 

[Eureka]

600-700W is a good range for 2 cards. 850W will give you a lot of headrooom with 2 cards, you might even be able to push 3 cards on it.

 

[icu222much]

Are you sure? I don't mean to question you, but the Newegg PSU calculator says I need ~825W, and I'm not sure if they factored in OC-ing GPU/CPU.

 

[Eureka]

Those calculators are always high... 850 isn't bad, but you should be able to get by with 700W too.

 

[icu222much]

What happens if I don't have enough power? Will my cards just fail?

 

[crazymonkeyzero]

What happens if I don't have enough power? Will my cards just fail?

Game play will studder or crash when you put load on the overclocked cards. Lol, newegg calculator is calibrated to get you to buy a more powerful psu than you need. After all, they are going to be pocketing the difference.



But seriously 700w+ is perfectly fine. Just make sure it has a single 12v rail in the specs.

 

[fffblackmage]

I was looking up power consumption for 7950 CFX and came across this: http://www.guru3d.com/articles_pages/radeon_hd_7950_crossfire_review_2_and_3_way,5.html

What would happen if your PSU can't cope with the load:

bad 3D performance
crashing games
spontaneous reset or imminent shutdown of the PC
freezing during gameplay
PSU overload can cause it to break down

Those calculators say you need ~800W of power because there are craptastic power supplies out there that are overrated. An excellent 650W PSU would power your computer just fine and provide you with cleaner power (less voltage ripples, better voltage regulation, and you get stuff like over-current protection and over-voltage protection) than any crappy 800W PSU.

And single vs multiple rails doesn't matter.

Actually, most of the stickies on top of the Power Supply subforum are excellent reads on PSUs in general.

 

[lehtv]

XFX 750W XXX edition $100
80+ silver
semi-modular
5-yr warranty
made by seasonic

Rosewill Capstone 750W $100
80+ gold
non-modular
5-yr warranty
made by superflower

 

[BFG10K]

As has been stated, 850W is absolutely overkill for that setup if it’s a quality PSU (i.e. one guaranteed to deliver its full rated power).

 

[dmoney1980]

XFX 750W XXX edition $100
80+ silver
semi-modular
5-yr warranty
made by seasonic

Rosewill Capstone 750W $100
80+ gold
non-modular
5-yr warranty
made by superflower

can't beat that with a stick!

 

[badboyeee]

Antec High Current Gamer Series HCG-750 750W ATX12V v2.3 / EPS12V v2.91 SLI Certified CrossFire Certified 80 PLUS BRONZE Certified Active PFC Power Supply

$55 AR @ Newegg:
http://www.newegg.com/Product/Produc...82E16817371049

 

[lehtv]

Where'd you put that stick, dmoney... .

And that's one of the Antecs with 5 year warranty no less. OP - grab it now.

 

[kleinkinstein]

Seasonic X650 @ $90 or X750 @ $100 on CM. Few, if any, compares!

 

[TemjinGold]

At nearly half the price, the Antec certainly compares.

 

[kleinkinstein]

Huh? How? I guess the silver lining is that you indeed don't pay for what you don't get in that Antec

4 rails? Oh my!
No Gold
No Modular
No Sanyo Denki San Ace PWM Silent Fan
No silent operation up to 45% load
7.1" long
Lot's of dead units after 12-18
Ho-hum and lackluster reviews
No wonder it's on discount. Antec must be trying to purge the shelves.

X750 wins

 

[aaksheytalwar]

I would get a seasonic x850 or x1000

 

[lehtv]

I would get a seasonic x850 or x1000

It's for 7950 crossfire, not trifire.

 

[TemjinGold]

I would get a seasonic x850 or x1000

Nono, play it safe man. Go with the EVGA NEX1500 for headroom!

 

[aaksheytalwar]

If you want to overclock really high, or at least keep the option open (coupled with 6+ hdds if needed) then 850 watts will be borderline. Just a single 7950 past 1200 with volt mod can use up to 250-300 watts at peak.

 

[badboyeee]

So whatcha getting OP?! Get Gold if only you game hours everyday or leave computer on 24/7. If you look at the other newegg reviews they all have their share of DOA units, even the seasonics.