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PSU question with 4870x2 and GTX 280

Last response: in Graphics & Displays
January 8, 2009 6:51:41 PM

I am looking on purchasing new GPU and i have Corsair VX550 ( and my system specs are AMD Phenom x4 9550 with 4 GB of 800MHZ RAM and 500 GB Sata HD and some sata dvd burner and my mobo is Asus M3A..

So my real problem is that can i get the 4870x2 even tho ati page says that my psu cant handle it i don´t want to get the 280 but it looks i might hafta get it
What do you guys think?
a c 143 U Graphics card
January 8, 2009 7:30:32 PM

The 550VX has 41A.

The BFG GTX 280 recommendation is 42A or more.

The HD 4870 X2 consumes about 94W more than the GTX 280 at its busiest times.
so let's say 42A + 94W/12V = 48A.

With either card you should get a new PSU. I'd recommend this PC Power & Cooling 750W, 60A, $80 after rebate

January 9, 2009 6:07:49 PM

Well according to Corsairs homepage my psu is sufficient for both of them are you sure about your calculations?

Or is the calculator just BS
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a c 143 U Graphics card
January 9, 2009 6:32:22 PM

My bad. I said "you should get a new PSU". I should have been clearer. It will work, just not in the optimal range of the PSU. It's not a very good idea, especially for the long term, but it will work anyway.

Video card manufacturers tend to pad their minimum PSU recommendations, to make sure they get fewer support calls and also to make the PSUs work at 70% or less. That's important because after about 70% load the PSUs start working less efficiently and the noise/heat/electricity bills go up. That in turn hurts the video cards and other parts. Also, PSUs tend to weaken in time (because of capacitor aging).

Try it, why not. Anandtech reviewers built this system and it consumed 407W under load:

QX9770 @ 3.20GHz, Intel DX48BT2, HD 4870 X2, Seagate 7200.9 120GB,
4 x 1GB Corsair DDR3-1333 7-7-7-20, Vista Ultimate 64-bit SP1

Your PSU can deliver 41A*12V=492W. It should be able to handle that. I'm assuming you're not going to have a lot of hard disks, TV cards, fans, lights, etc, because then you might push the PSU too much and it will shut down.

a c 177 U Graphics card
January 9, 2009 6:38:30 PM

And to add more fuel to the fires; ATI reccomends the TX650 (52A 12v) as the minimum Corsair supply for the 4870X2, which gels with AEVMs` calculations.
I would strongly advise you to accept the advice of AVEM and upgrade your PSU if you intend to use either of the cards you mention.
a c 259 U Graphics card
January 9, 2009 6:50:17 PM

Your psu has two pci-e connectors, one 6 pin, and one 6+2 pin. A quality unit will be able to power those connectors to their maximum power draw. Corsair is a quality unit. You can buy either vga card.
A psu operates most efficiently in the middle third of it's capability. If it needs to operate near the top of it's range, it will become less efficient, the fan will spin up and get noisy, and on a poor quality unit, the power will fluctuate out of spec.

I suggest that you try the 550vx. As suggested before, the VGA vendors recommendations are very conservative; in part to account for older or poor quality psu's.
a c 143 U Graphics card
January 9, 2009 6:55:53 PM

Excellent point. Those recommendations assume some pretty wild claims from PSU manufacturers. Look here:

The first PSUs that claim 550W on that list deliver 30A,30A,32A, refuse to disclose, 38A, 44A (kudos to Amacrox for this one), 30A,35A, etc. Yours with 41A is one of the best.

January 10, 2009 3:27:01 AM

Thanks.. I will give it a go i currently have "only" one 4850 and atleast with load the psu seems to work great pretty good noise level and all...

And now i will not have many hard drives or usb devices connected just my keyboard and mouse most likely....

And what comes to my components ages all of them has atleast 5 years of warranty the psu has 8 years so i really do not care about the age of capacitors