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  Power requirement question 
 
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Tennessee Nov 29, 2010, 11:28am EST Reply - Quote - Report Abuse
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In assessing a computer in which a second video card is needed, how should I determine the power requirements?
Specifically, if both video cards recommend 400W minimum, does that mean I need at least an 800W power supply?
Thanks!


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Michael C Nov 29, 2010, 11:30am EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
Most websites (AMD, Nvidia) will have the power requirements listed for each card. What cards do you plan on using?

Bungle Nov 29, 2010, 02:28pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
Depends on the cards... that 400W figure includes what is required to run the rest of the system.

Core i7 4770K @ 4.4GHz | Corsair H110 | Gigabyte GA-Z87X-UD5H | 32GB 1866MHz Corsair Vengeance
2x EVGA GTX 780 SLI | 256GB OCZ Vector SSD | 4TB Hitachi 7K4000
Corsair AX1200 PSU | Corsair 650D | Windows 7 Ultimate x64
Tennessee Nov 29, 2010, 04:20pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
I have two computers that have an AGP FX5200. I was looking to add a PCI GeForce 8400GS. From what I have read, it looks like both cards recommend a minimum power supply of 300W, but on a different page I saw 400W minimum was recommended for the 8400. I don't know who to believe or what power supply to upgrade to...the machines have stock low wattage power supplies (280 or 305 I can't remember off the top of my head).

Michael C Nov 29, 2010, 04:28pm EST Reply - Quote - Report Abuse
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Edited: Nov 29, 2010, 04:28pm EST

 
>> Re: Power requirement question
Would I stick a 8400GS into a PC with a 300w psu? No. I wouldn't take that chance. 400w maybe.

Bungle Nov 29, 2010, 04:31pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
I would try it and if the system is unstable then worry about it. I don't think low end cards like that require an AUX power connection. The PSU that came with the system should be adequate... assuming there isn't a bunch of other cards in the system.

Core i7 4770K @ 4.4GHz | Corsair H110 | Gigabyte GA-Z87X-UD5H | 32GB 1866MHz Corsair Vengeance
2x EVGA GTX 780 SLI | 256GB OCZ Vector SSD | 4TB Hitachi 7K4000
Corsair AX1200 PSU | Corsair 650D | Windows 7 Ultimate x64
Bungle Nov 29, 2010, 04:35pm EST Reply - Quote - Report Abuse
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Edited: Nov 29, 2010, 04:37pm EST

 
>> Re: Power requirement question
If you want to be sure that they computer has enough power consider upgrading the PSU along with the graphics card. You should be able to get a decent 500W or so PSU under $100. I personally prefer to stick to Corsair or PC Power & Cooling... you'll pay a premium but the power they supply is better than what you get from a really cheap unit (It and your parts will last longer too). Thermal Take, Antec, Enermax are not bad choices either. You should look for a unit with a single 12V rail and if the computer is a Dell you'll need check and see if the PSU is standard ATX or a proprietary design ( they were doing that a while back and im not sure if they still are or not )

Core i7 4770K @ 4.4GHz | Corsair H110 | Gigabyte GA-Z87X-UD5H | 32GB 1866MHz Corsair Vengeance
2x EVGA GTX 780 SLI | 256GB OCZ Vector SSD | 4TB Hitachi 7K4000
Corsair AX1200 PSU | Corsair 650D | Windows 7 Ultimate x64
Tennessee Nov 30, 2010, 07:23am EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
Yes, I will be upgrading the PSU with the video. But I do want to make sure I was clear in my original question...I will be running two video cards...not replacing the old one with a new one. That being said, do you still think 500W is sufficient to run dual video cards? This power stuff is messing with my mind (or what's left of it)!

john albrich Nov 30, 2010, 11:43am EST Reply - Quote - Report Abuse
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Edited: Nov 30, 2010, 11:46am EST

 
>> Re: Power requirement question

If you type [psu calculator] into a net search field, you'll find some tools that are available to help estimate the power requirements of a given system configuration.

I would take the resulting Watts number and add 20% for a safety factor and to provide a power buffer for future expansion.


Edit to add:
I'd also try several of the tools to check if they are at least somewhat consistent in the final figure, and (being my very technically conservative self) probably take the highest "reasonable" value as the "resulting Watts number".

PIRATE Nov 30, 2010, 02:18pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
what I am curious about, what exactly is it being tried to achieve by having:

AGP Fx 5200

and PCI 8400.

Can a card act as a Physx card? Or do you want 2 videocards to swtich from one to the other?


------------------------------------------------------------------------------------------------------------
Intel Core 2 6400 2.1ghz / ASUS SLI Deluxe / 4gb DDR2 800 G.Skill / ATi Radeon HD 3870 512mb OC / 7 years old Seagate Barracuda 160gb 7200
Bungle Nov 30, 2010, 03:14pm EST Reply - Quote - Report Abuse
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Edited: Nov 30, 2010, 03:14pm EST

 
>> Re: Power requirement question
I know there are hacks out there that let people do it but from my experience ATi and nVidia drivers do not play nice together. If you're going to run two cards you should save yourself the headaches and run two from the same GPU vendor.

I also question the purpose of running such a setup... Get a single more powerful GPU and be done with it. As for running two low end GPUs on a [good] 500W PSU... shouldn't be an issue.

Core i7 4770K @ 4.4GHz | Corsair H110 | Gigabyte GA-Z87X-UD5H | 32GB 1866MHz Corsair Vengeance
2x EVGA GTX 780 SLI | 256GB OCZ Vector SSD | 4TB Hitachi 7K4000
Corsair AX1200 PSU | Corsair 650D | Windows 7 Ultimate x64
Tennessee Nov 30, 2010, 04:27pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
Good questions:

I have four computers in an office environment that already run dual monitors. They each require a third, and potentially fourth monitor. Three of the four have existing dual-head Nvidia GeForce cards, the other one is ATI Radeon. Seeing as I only have PCI slots available for expansion, I was looking to add an additional card to support the additional monitor requirement. (This is not a graphically-intense environment...just stock business apps and browsers.)

In today's economy, I am of course expected to do this on a minimal budget. That is why I was looking at cheaper cards and power supply upgrades.

But that leads to another question: do you see a better way to accomplish the mission without spending a pile of money? If anyone has a better idea, I am certainly open to options.

And thanks to everyone for your input thusfar...I appreciate the help.

Tennessee Nov 30, 2010, 04:29pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
PS:Yes, I was planning on keeping ATI with ATI and nVidia with nVidia. I think that might border on mixing oil with water :)

Bungle Nov 30, 2010, 04:35pm EST Reply - Quote - Report Abuse
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>> Re: Power requirement question
If your video card doesn't have enough heads on it to drive the number of monitors you need you're doing the right thing by buying more video cards... thats the only way I know of to accomplish what you want to do.


Core i7 4770K @ 4.4GHz | Corsair H110 | Gigabyte GA-Z87X-UD5H | 32GB 1866MHz Corsair Vengeance
2x EVGA GTX 780 SLI | 256GB OCZ Vector SSD | 4TB Hitachi 7K4000
Corsair AX1200 PSU | Corsair 650D | Windows 7 Ultimate x64

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