Is a 550W PSU enough for my build?

Jan 23, 2015
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Hi there, so next month I am going to make my own PC and I am thinking about buying a Seasonic G-Series 550W 80plus gold PSU, however I am afraid that might not be enough for my build, here are the components and their respective power requirements:
Intel Core i7-5820k 6-Core 3.3 GHz 15MB - 140 Watts
ARCTIC Liquid Freezer 120 CPU Cooler - 15 Watts
EVGA Nvidia GeForce GTX 970 Superclocked ACX 2.0 4GB Edition - 170 Watts (requires at least a 500W PSU according to the manufacturer's website)
2x G.Skill Ripjaws V Series 8GB 2133 MHz DDR4 RAM - 11 Watts
MSI X99A SLI - 70 Watts
Western Digital Caviar Blue 1TB EZEX 3.5" 7.2K HDD - 20 Watts
Samsung 850 EVO 500GB 2.5" SSD - 10 Watts
That makes a total of 436 Watts required to run my build, however I hear that sometimes there are peaks in power consumption that might go over the 436 Watts, so I was advised to purshase a PSU that was ate least 50 Watts more power than what was required to power my components, so I think the 550 Watts might be enough but I am not entirely sure if that is a safe purchase or if it is safer to get a 600/620/650 watts PSU or of those are just higher than what it is required even on a high consumption scenario.
Thanks
 
Solution
Don't use calculators, they aren't necessarily accurate. A 70W motherboard? Yeah right.

You have nothing to worry about. Your system is about 350W max. Gaming load will be more like 275W, putting you in the sweet spot for efficiency.
watts / volts [12] = amps

so all ways use max power draw like say your chip stock is 140w [with out a overclock] 140w / 12v = 11.7 amps just for it

EVGA Nvidia GeForce GTX 970 Superclocked ACX 2.0 4GB Edition - 170 Watts ? [maybe ? shows peak at 188w] that's 16 amps

now you know the rest to do [ I also like to add maybe 10 amps for any ''overhead'' that may pop up in a oc or hardware change ]

550w with a true 46a at the 12v+ is bottom line limit to me no room for error if anything you run pulls over what you figured up above maybe a 650w with 54amops at the 12v+ is a better ''safety '' buffer zone ?? [opinion]
 

CapyWarrior

Commendable
May 23, 2016
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I would say the 550w is probably capable of dragging that build along. However, PSUs tend to degrade over time and are also incredibly annoying to exchange. Your build is fairly future-proof but i'd get a better psu for safety. That's a pretty high-budget in general and there's no reason to be cheap on a single part. Go for at least a 650w gold-certified power-supply and you should be fine.
 


I wouldn't say a G-Series 550 is "cheaping out". It's a good power supply. And perfectly sufficient, not underkill at all.
 

CapyWarrior

Commendable
May 23, 2016
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I'm not trying to say that it isn't a good power supply. What I'm saying is that relative to the other parts, it isn't quite as "high-end." Building a computer with a power supply that ends up not being enough is awful and I would certainly err to the side of caution. I also don't think a 350w power supply would be sufficient at all. It just isn't enough.
 

lateralnw

Distinguished
Dec 30, 2007
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I found a site that says under load the i7 5820K will pull 185 Watts
The hard disk will most likely pull about 2 amps 24 watts on startup
The video card I'm not sure but would expect it to draw more power when under load also.

Is that important to keep the power supply wattage down? Price I guess plays a part.
I had played around with power supplies a while ago and had a few issues. I couldn't put my finger on what the problem was so I ended up with a 775Watt unit.
I do run from time to time many hard disks and some heavy cpu and graphic processing. Best part is I don't even think about the PSU, it just works.

 


High quality 550W PSUs can sustain a higher power on the energy outputs than their labelled wattage. They can maintain a steady 600W usually, for example, while keeping voltages intact and before OCP or OPP kick in anyway.