Is 620W enough for my new system?

michaelru

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Jan 6, 2012
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Hi!
this is the system i'm getting:

CPU: Intel I5 2500 3.3GHZ

CPU cooling: Scythe KATANA 3

GPU: 2*SAPPHIRE HD 6870 1GB GDDR5 in crossfire

Motherboard: Gigabyte GA-P67X-UD3-B3

Ram:2*Crucial 4GB DDR3 -1333

Case: Fractal Design core 3000

HDD: 2*western digital black caviar 500GB

I was thinking of getting the "Seasonic 620W Modular Active PFC Retail 80 Plus Bronze" but i'm not sure that 620W will be enough.
the system will be used for heavy gaming...

so what do you think, is 620W going to be enough for this rig or should i get 650W/700W psu?

Thanks! :)
 
A quality PSU like that will handle it fine!
From HIS HD6870 page "500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for AMD CrossFireX™ technology in dual mode)"
 
For a system using two Radeon HD 6870 graphics cards in 2-way CrossFireX mode AMD specifies a minimum of an 600 Watt or greater power supply. The power supply should also have a combined +12 Volt continuous current rating of 40 Amps or greater and have at least four 6-pin PCI Express supplementary power connectors.

The Seasonic M12II-620 Bronze (SS-620GM), with its +12 Volt continuous current rating of 48 Amps, is electrically sufficient. The only problem is that it only has one 6-pin and one (6+2)-pin PCI Express supplementary power connectors.

Instead, choosing the Seasonic M12II-650 Bronze (SS-650AM), with its +12 Volt continuous current rating of 53 Amps and four (6+2)-pin PCI Express supplementary power connectors, will be more than sufficient to meet the requirement.
 
your psu will be maxed out or even pushing over volting... you really do need some headroom as you want to have multiple storage devices... 700+ would be safer as not all 650w rated psu's deliver even 600w constantly... times the amps by 12 and you will get the true constant rating of the psu... its likley to be around 570w if your lucky and bought a quality 1... your build will use 190x2 for the gfx 95w for the cpu 30 for oc'd motherboard 10w per fan 20w per hdd 10w per ssd 40w per dvd/br burner. so you will be pushing 600w if everything was going full tilt, luckly your systems average draw will be around 450w so you should be ok... if its a single rail psu.
if its a dual rail then you will have issues and will need to give your system a 200w headroom boost ie 750w or even 800w just to be safe.
 

OP is discussing quality PSU's that deliver! Here is several cards measured total system load on overclocked LGA1366 system and 2 x HD6950 in CF is at 509watts running stress test! 2 x HD6870 will consume less!
http://www.anandtech.com/show/4239/nvidias-geforce-gtx-590-duking-it-out-for-the-single-card-king/16
 

michaelru

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well, i guess i'll go with the SS-750HT.
oh, one more thing-is the case that i've chosen will be ok for this system? (i mean, will everything fit and ventilate properly?). the case is Fractal design core 3000
 
Fractal Design Core 3000

• Supports graphic card lengths up to 270mm (10.6 inches) when removable HDD-Bay is in place

• Supports graphic card lengths up to 420mm (16.5 inches) without removable HDD-Bay

• Supports PSU's with a maximum depth of approximately 160mm, when the bottom 120mm fan location has a fan mounted. When not using the bottom 120mm fan location, the case supports longer PSU's, typically 250mm.

The Sapphire Radeon HD 6870 is 245mm (9.65 inches) in length so they'll fit in that case.

The Seasonic S12D-750 (SS-750HT) is 160mm (6 19/64 inches) in depth so it will fit even if you have a case fan mounted at the bottom of that case.

Ventilation should be fine.
 

truegenius

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a minimum of 500w at 12v is required (means around 42A at 12v rail (combined)) to run crossfire without any overclocks, and thus a psu of 650w is minimum recommended (700w-750w due to aging)
 

i guess you didnt read or understand my post... i said his typical load would be about 450w and would potentialy max out at 600w if everything was running maxed out. meaning all the drives and rom burner.

that system you linked to has a 500+w draw without any extra drives just a single ssd... so please if your gonna try and teach a granny to suck an egg, make sure she doesn't already know how to do it just as well or better than you.

not being funny here m8, but i do know what im talking about ;) or i wouldnt have replied... im funny that way...
 


That's a cute line, here's one from your other post.
" times the amps by 12 and you will get the true constant rating of the psu" ?
You sure you know what you're talking about ?
 

truegenius

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"40ax12v=480w is the max output for that 620w rated psu"
[:truegenius:1] to be precise , it is power at the 12v rail only (not total :non: )
 

You get the 12v output.
Here's an example for you
antec500.jpg


Is that a 408 watt psu ? Or a 500 watt psu ?


 

You editted your message while I was responding
That's a typo , right ?
 
well it sorta says what the psu is rated at on the lable... its rated at 500w but its max constant load is 408w... i just use my method as a rule of thumb... yeah it is a typo it should be 40x12 .... sry about that i just woke up 30 mins ago...

as for the other 1 you listed. (17a@x2)x12v gives 408
 

Put a little correction there.
Here's where I think the problem lies,
It's not a complete 12v world yet, even the most basic system will use 2 or 3 amps worth of power from the 3.3 and 5v rails, those rails are included in the " constant rating " of a psu.
 

No offence taken, just trying to keep it real.