Will 550w be enough for 2x8800 GTS, AMD 6000 and 3 Gig of RAM?

drog1998

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Hi There,

i've just ordered a second 8800 GTS to run in SLI and I was wondering if I have enough juice to power a second card?
I did a check on the online Extreme Calculator http://www.extreme.outervision.com/psucalculatorlite.jsp and it came out at 430 W which is with in what i've got bu just thought I'd ask for a second opinion.

My specs are:
AMD X2 6000
Gigabyte M57SLI Mobo
2 x Gainward 8800 GST in SLI
3GB of RAM
1 x 7,200 HDD
1 x DVD Burner/Player
and about 5 Fans in a Nine Hundred case

Many thanks.
 

Ibanezrg570

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Generally a large flame and a loud pop, followed by the pleasant smell of burnt electrical parts.

Best case scenario: New PSU to replace the burnt one.

Worst Case: Burnt hardware, including GFX Card(s), motherboard and anything basically in the PC.
 


spontaneous reset or imminent shutdown of the PC
PSU overload can cause it to break down

With only 30 amps of +12v power on your psu you'll probably have a problem.
 

badgtx1969

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Don't think so:

The Antec 550w True Power V2 has two 12V rails that can do 19A max (and maxed together it drops to 36A). You need a minimum of 26A to run ONE 8800 GTS. :non:

I wouldn't risk ruining any of your components, you can probably get a decent PSU that can handle it for ~ $150 or less.
 


Sorry, I gave the amperage for the 430 watt model :(
 

chookman

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"The TruePower 2.0 lists each 12V rail has supplying 19A of power. But if all the voltage rails were to be totaled up, this would be greater than 550W of power. Each rail has the ability to get up to 19A, but the footnote below clarifies this by saying the maximum of the two combined is only 36A"

Thats off compreview

This is for a 8800GT off eVGA site
"Minimum of a 400 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 22 Amp Amps.)
Minimum 450 Watt for SLI mode system.
(Minimum recommended power supply with +12 Volt current rating of 24 Amp Amps.) "

This is for 8800GTS 640mb SSC eVGA... They dont have listing for SLI for this card
"Minimum of a 400 Watt power supply.
(Minimum recommended power supply with +12 Volt current rating of 26 Amp Amps.) "

Seems to me that adding a second GPU doesnt mean that you need huge power increase as these figures are based of running a whole rig.

Taking a look here
http://www.atomicmpc.com.au/forums.asp?s=2&c=7&t=9354
We see 8800GTS SLI will use max ~200w...

EDIT: This tells me it would actually only use ruffly 16amp on the 12v rails for the GPUS

Taking into account aging of PSU, i would think that you should be right but on bare minimum.
 

mlhm5

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The answer is no. Your power supply is not SLI 8800 confirmed.

Pick one from this list

http://www.jonnyguru.net/forums/showthread.php?t=103

The Silverstone ST75ZF is $149 from Tiger Direct
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=2604213&CatId=2533
 

chookman

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EDIT: This tells me it would actually only use ruffly 16amp on the 12v rails for the GPUS

Ruff, ruff!! :whistle:


This is of course for running the 2x GPU's only...

Everybody seems to think that current GPU's and SLI use MASSIVE amounts of power when they dont. Any quality ~500w will do it (unless its like a GTX or ultra or something).
 


That minimum recommendation depends on exactly what components you are using.
 


The things you need to worry about are the components that draws power from the 12v rails of the PSU.

8800GTS 640MB (x2).........................106w x2.........212w GPU Power Consumption
AMD 6000+.........................................................130w *
1 HHD.................................................................12w
1 DVD Burner........................................................12w
5 120mm fans.......................................................30w

Total Max Power Consumption on 12v rails...............396w
Total Max Amperage.............................................33A

* This is based on the power consumption of the AMD 5000+ @ 2.6GHz vs. 3.0GHz for the 6000+.

AMD 5000+ Power Consumption

The above estimate assumes you are not overclocking and every single component is working at 100% load.

The PSU you want to get should generally be about 20% more than the estimated in case you want to drop in a couple of upgrades later. That means you should by a PSU with 40A; more if you know you will be dropping in a lot of power hungry upgrades in the near future.



 
Since the Antec 550w provide 36 amps, that means at max capacity the consumption on the 12v rails will put an estimated 91.6% load on the PSU's 12v rail.

In the short term you should be okay. Antec's PSUs are merely good in my opinion and should be able to handle that load until you buy a better quality and maybe more powerful PSU.

I generally recommend Seasonic PSU so at a minimum I would suggest the Seasonic S12 550w PSU which can provide 41 amps on the 12v rails:

Seasonic S12 Energy Plus 550 = $116 after rebate.

Other suggestions:

Seasonic S12 Energy Plus 550 = $160

CORSAIR CMPSU-620HX = $150 after rebate (made by Seasonic)

PC Power & Cooling Silencer 610 EPS12V EPS12V 610W = $119 + 9 shipping (made by Seasonic)

 

chookman

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Basically what i was trying to say minus the awesome explaination. ;) thanks Jag
 

drog1998

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Thanks so much for the detailed replies. I will stick with what i've got but should i make and changes I'll know it's time for a PSU upgrade.

Thanks again.
 

drog1998

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Just a quick update.

I've installed the second card in SLI with no problems so it looks like the PSU was powerful enough.

If anything i'm just a little dissapointed in the difference it's made. 9500 before and 11200 on 3D Mark 06. And Crysis runs like crap