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Is a 750W PSU enough for this build?

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Faye

Faye

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Jul 2, 2011
Location
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I went through Corsair's "PSU Finder" and it recommended a 650-750W PSU, but I thought I'd double check here. Also, the Finder doesn't include other ext. cards, devices or drives in its calculation, so it made me wonder a bit.

i7 4930k (probably with slight OC)
Asus x79-Deluxe
GTX 580 Matrix Platinum
32GB 1600Mhz DDR3 RAM (will update to 64GB at some point)
Xonar Essence ST sound card
1 SSD
2 internal HDDs
1-3 external HDDs (connected most of the time)
1 BR/DVD drive

Also, now when we're on the subject, which Corsair's PSU would you recommend? I've been out of the loop for a few years, so I'm not sure which are considered the most reliable nowadays. Sadly I've had quite bad experiences with Corsair's PSUs, especially those considered "very good". For example, currently I have a HX750 and since the start it has had the problem of super-noisy "fan surges" (as described by this dude). And before that I had to RMA two TX650s as both went dead in a month after installing. But I'm still willing to give Corsair a chance, because before these latest problems I never did had any issues with the brand.

Thanks in advance!
 
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A 750W is overkill.

I would get a Seasonic G550 for that, personally.
 
Wow, really? In that case I seem to have been seriously overestimating general power consumption for a long time. Thanks for the heads up!

Btw, if 550W is enough, why does Corsair's PSU Finder claim I need 650-750W? Would think they'd try to be as truthful/realistic as possible.
 
PSU calcs overestimate for the sake of your PC's safety essentially. There are CRAP PSUs on the market that cannot put out what their label says so they alwaty overestimate. But think of it this way, your CPU at WORST case is 130W. Perhaps 150W with "a little overclocking (like me). The GPU 250W at WORST stock. The rest of your system isn't close to 100W, likely around 50-75W at most... = 450W at WORST with CPU stressed 100% and GPU stressed 100% (not typical unless you F@H or something of the like). A quality 550W unit is fine.

I run a 4930K @ 4.2Ghz ~1.2v and a GTX 780 Lightning with a 560W PSU and the fan barely spins up on it. ;)
 
Faye said:
Wow, really? In that case I seem to have been seriously overestimating general power consumption for a long time. Thanks for the heads up!

Btw, if 550W is enough, why does Corsair's PSU Finder claim I need 650-750W? Would think they'd try to be as truthful/realistic as possible.
Click to expand...

Every calculator overestimates horrendously. Add up your TDP, toss on 20% for a heavy OC, and then you'll see what I mean.

130W + 243W + 50W (mobo/RAM/HDD) = 423W under full load.
Adding 20% to CPU and GPU, you're still under 500W at full load.

Note: Full load is NOT gaming.

Seasonic G550. It pushes 540W on its 12V rail alone. You're good to go. Especially since you'll rarely push TDP, much less TDP+20%.
 
Yeah, with those estimated Ws I can see that 550W would be sufficient. Thank you both for breaking it down for me.

This build is mainly meant as my workstation for heavy After Effects rendering and VFX/color correction + editing with Premiere (+Photoshop/Illustrator etc.), but I assume even this won't put the 4930k on full load? Just checking to be sure. On my previous OC'd i5-750 I couldn't really do anything else (except for browsing and other "light" stuff) while rendering in AE or exporting from Premiere. So I bought the 4930k with more efficient multi-tasking in mind, hopefully it's up for the job :)

I'll go with the Seasonic!
 
Faye said:
I have a HX750 and since the start it has had the problem of super-noisy "fan surges" (as described by this dude). And before that I had to RMA two TX650s as both went dead in a month after installing. But I'm still willing to give Corsair a chance, because before these latest problems I never did had any issues with the brand.

Thanks in advance!
Click to expand...

I would stay away from Corsair PSU Iv seen few people complaining of dead and blown PSU and motherboards. Go with seasonic.
 
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EarthDog said:
The GPU 250W at WORST stock.
Click to expand...
I forgot to mention that I have two HD monitors, do you think it makes much difference? I did read that with GTX580 Matrix one monitor consumes ~21W and two ~80W. And then I read this:

http://www.geeks3d.com/20110612/asus-rog-matrix-gtx-580-platinum-review-overclocking/7/

Where apparently with default settings and full load it consumes 271W. Does this mean that with two monitors the default settings+full load goes up to 330W (271+59)? Or am I totally over-thinking this? I'm suspecting that the GPU might go at full load while rendering in AE, for example.

Then 330+150+75=555W?

*overly-paranoid of computer asploding* :rolleyes:
 
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Your monitors are not plugged into the psu...they are plugged into and get power from the wall.

Theh used a power virus app and is an estimate.
 
EarthDog said:
Your monitors are not plugged into the psu...they are plugged into and get power from the wall.
Click to expand...
Heh, yeah I understand this. But "two monitors connected to the tested card" seemingly (according to the test) still affects how much power the card itself consumes.

Anyway, I'm not arguing - I am going with the Seasonic 550. I do trust your judgement vastly more than my own :D Thanks again for the help.
 
At idle, they do consume more, correct, as I believe it does not clock down to the 2d clocks with multiple monitors but does with one. At load it wouldn't be any more than it's rated to do. :)
 
EarthDog said:
At idle, they do consume more, correct, as I believe it does not clock down to the 2d clocks with multiple monitors but does with one. At load it wouldn't be any more than it's rated to do. :)
Click to expand...

Ding, ding, ding, we have a winner.

GPU won't clock down typically with multiple monitors, increasing power consumption.

Same thing as not letting your CPU idle down by cutting off the "green" functions.
 
bob4933 said:
My suggestion... get the 750w anyway. The price difference in almost all circumstances between a 500w and comparable 750 watt is peanuts. 10-15$ usually. Unless you're finding a sick deal on a 500w, I would say go for the breathing room the 750w offers.

edit
give these a looksie

http://www.newegg.com/Product/Produ...301&nm_mc=AFC-IR&cm_mmc=AFC-IR-_-na-_-na-_-na
Click to expand...
:facepalm:

I believe that was one of the CXs ED referred to also.

I'd still go the Seasonic.

I stuck one of these in a recent rebuild and they are manufactured by Seasonic just to throw it up there.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817371071

Actually even a rebate on these atm and a litle more umpf after looking at that, so even cheaper.

http://www.newegg.com/Product/Product.aspx?Item=17-371-072
 
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Count connectors too. You list 4 SATA internal devices. (I'm assuming the external SATA devices have their own power supplies.) Do the smaller PSUs have this many SATA power connectors? Adding splitters is not a big deal but could easily make a smaller PSU as expensive as a bigger one.

I'd also be looking for a modular PSU if not too much more expensive. Keeps the inside of the case a little neater which will pay off when you need to get back in there and clean out the dust bunnies. ;)
 
MongGrel said:
Modular is nice but *shrug*
Click to expand...
After I posted that, I wondered if it was even a good suggestion. it does mean extra connections where the cables connect to the PSU and those are additional points of failure. I don't have a modular PSU but just wished I did when I was trying to figure out what to do with the octopus of extra cables in my present system. (Not brave enough to just snip them off in case I ever need them. ;) )
 
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