Is my OCZ StealthxStream 700w PSU Strong Enough

[syxxnyne69]

im planning on running a 5770 cf setup as it fits into my budget better than a 5870 and according to the best pcie test here its provides better performance than a 5850. im just wondering if the psu i have chosen is going to be able to handle it along with the core i7 860 and 4gb of ram that are in there aswell

OCZ StealthXStream OCZ700SXS 700W

 

[syxxnyne69]

1000watts i think thats quite ridiculous condering my ati hd 5870 was only going to take a 550w to power my entire system. i do little to no video editing at all. i make slideshows about twice a month. transcode videos using convertxtodvd about 5 times a week. and play total war series games and rts games on a daily basis . possibly going to get into cod mw2 on pc as i already love it on the 360

here is why i initially have chosen the hd 5770s And for $100 less, a couple of Radeon HD 5770s in CrossFire will keep up with the 5870 and offer the same DirectX 11 capability to boot.

 

[syxxnyne69]

no no my mistake not my system my bosses that the 5870 is on, i say my because when im at work he lets me be on the damn thing all day long

 

[MagicPants]

I have to say I think you are getting some bad advice here. I think a 700 could do 5870 in cross fire but just barely. 1000 watts is overkill though. To be safe I'd go with an 800 watt PSU.

Tom's did a review on this that should help:

http://www.tomshardware.com/reviews/radeon-hd-5870,2422-20.html

keep in mind you want about 20% headroom so that you're not "redlining" your PSU.

Also StealthXStream only has 675 watts on the 12v rails so that's a bit tight.

Corei7 processors do not need 500 watts by themselves. At load they consume between 200( for the 920) and 250( for the 965) watts.

 

[randomizer]

Please ignore all advice from the previous users (not including MagicPants), they were merely here to troll.

 

[skora]

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

Plenty of other calculators out there. The real hiccup is that its the 12v amps that matter more than total watts. But 56a on the 12v rails should be more than enough for a 5770 CF system. They use less power than my 4850 and my 550w Corsair is certified CF for a pair of 4850s.

 

[MagicPants]

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

Plenty of other calculators out there.

Those calculators tend to run a bit low. For instance it tells me a core i7 920 system with 285 sli needs just 585 watts but you can see it in the article a real system like that consuming 620 watts.

 

[skora]

Those calculators tend to run a bit low. For instance it tells me a core i7 920 system with 285 sli needs just 585 watts but you can see it in the article a real system like that consuming 620 watts.

Measuring from the wall will always show more power going in than power coming out. PSUs don't convert 100% of AC power into 100% DC power. You get XX% DC power and the rest is waste and lost as heat. The Coolermaster 1100 UCP from you linked article is 80+ Silver. So at just over 50% of capacity at a load of 585w, you'll be running about 88% efficency. 620w AC x .88 efficiency = 545w DC being used. So the calculator is actually overstating by 40w what that system would need.

So if you only need 585w to run a pair of 285s on an OC'd i7 920, 700w will be more than enough for a pair of 5770s and still keep the PSU running in the most efficient range around 50% of capacity. Using the calc I linked, with an OC'd 1.45v CPU, 2x 7200 HDDs, 2x DVD burner, 2 extra fans, only came out to 374w. The OCZ 700w actually turns out to be a great fit for the planned system and has some headroom if you want to upgrade and push it a little harder in the future.

 

[syxxnyne69]

Best answer selected by syxxnyne69.