PSU for Core i7, 580W enough?

[Fr33m4n]

I just ordered a new system online consisting of:

Gigabyte GA-EX58 Extreme
Corsair TWIN3X DDR3-1333 4096 MB (2 x 2048 MB)
Gigabyte Radeon HD 4870
Intel Core i7 920

I didn't order a PSU yet cause I was kinda hoping that my old one would still be up to the task. The one I currently have is:

Tagan 580W

But I don't want to take any chances so what I'd like to know is whether there is a way to calculate if this will be enough or if I need to get a better one. I might do some light OCing

If I need to get a new one, then I have been looking at the:

PC Power & Cooling Silencer 750 750W

Is that a decent choice?

 

[dajeepster]

Originally posted by: Fr33m4n

If I need to get a new one, then I have been looking at the:

PC Power & Cooling Silencer 750 750W

Is that a decent choice?

I'm running two of my i7 920s off of that power supply with no problems at all.

1st rig:
i7 920 (water cooled)
Asus P6T Deluxe
6gigs Patriot Extreme 1600
WD Velociraptor 300gig
ATI radeon 4850
6 various sized fans
water pump

2nd rig:
i7 920
MSI X58 platinum
2gig DDR3 1333 (being replaced with 6 gigs Super Talent 3x2 DDR3 1333 CL7)
XFX 9400gt 512mb
WD 640Gb Blue drive

 

[Fr33m4n]

Do you know exactly how much power that first system of yours is drawing? Also, how silent would you say that particular PSU is? Did you look at any other PSU's as candidates for your builds, and how did you figure out how much Wattage you wanted from your PSU?

 

[dajeepster]

Originally posted by: Fr33m4n
Do you know exactly how much power that first system of yours is drawing? Also, how silent would you say that particular PSU is? Did you look at any other PSU's as candidates for your builds, and how did you figure out how much Wattage you wanted from your PSU?

i haven't done a breakdown yet to see what the various parts would draw from the psu along with the total wattage drawn from the psu. The psu itself draws @ 270 Watts from the wall when measured with a killawatt under full cpu load. I haven't measured it yet under full cpu and gpu load yet.

 

[Fr33m4n]

I found eXtreme Power Suply calculator at this link

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

I inputted my my system with a little extra so that I knew I had some headroom and the calculator suggested that I need a 1207Watt PSU! Wow! I had to do it one more time in order to make sure I was inputting the right values and that I had adjusted for OC it still gave me a whopping 1080Watt suggested PSU! Could this possibly be right? Imagine going SLI or CrossFire on this thing. There wouldn't be a PSU in the world that is strong enough according to this.

EDIT! Nope, this thing is definitely defective. Selecting the i7 eXtremeedition CPU with OC AND 3-way SLI (and a whole bunch of other devices) only need 850Watts according to this calculator.

 

[Horsepower]

WOW! Great calculator. I just got the 750W silencer and it recommended 663W

 

[Flipped Gazelle]

Originally posted by: Horsepower
WOW! Great calculator. I just got the 750W silencer and it recommended 663W

No way your rig (at least the one in your sig) requires 663W.

As Fr33m4n stated, it looks like there's something wrong with that calculator.

 

[OCGuy]

That calculator is part of the problem...it grossly over-estimates power usage.


It told me I need a 1000W+ for my system, when it probably never sees over 550W @ load.

 

[magreen]

A good 350W psu with most of its power in the 12V rail would power your single 4870 system fine. It would be pushing it, but it would work. The i7 920 does not draw a large amount of power.

Either that online calculator is broken, or you entered your info wrong. Did you say quad-core cpu or quad cpus? I'm guessing you said quad cpus so it thinks you mean a 4 socket monster.

I don't know your particular psu, but a decent quality 500W psu would be plenty for your needs.

 

[OCNewbie]

If this is your current PSU - Link, then it should be plenty to power your system. They didn't give it a stellar review though.

 

[shempf]

don't forget to subtract for lack of efficiency. 650W+ is a waste of $$ & electricity for what is listed

 

[magreen]

Originally posted by: shempf
don't forget to subtract for lack of efficiency. 650W+ is a waste of $$ & electricity for what is listed

That's not really true, unless the psu in question has a very narrow power efficiency curve. Most modern high-efficiency psus (and especially the 80+ certified ones, since that's what 80+ means!) have high efficiency across a wide range of loads, whether loaded at 20%, 50% or 80%. If your power draw is 300W and you buy an 80+ certified 1000W PSU, you'd be loading it at 30% and it would use no more electricity than a 350W 80+ certified psu at the same 300W load. That's just an example -- I'm not saying the OP needs a 1000W psu (as I posted above).