What is the mnimum PSU for this spec?

tedstokes168

Hey all,

Question 1,

Right, here we go. I have a ATI 2900 HD card on order and have found
that my slow old PSU wont be able to cope with it, I am now looking
at getting a AMD Athlon64 X2-6000 and a Crossfire compatible motherboard
so I can have a near ultimate gaming PC.

Now to the question, with 2 ATI 2900 HD cards and the Athlon 64 x2 6000
what is the minumum spec power supply unit I can use, would a 700W do the trick or do I need to go to the higher more expensive ones? I have tried those internet wattage calculators and keep ending up with around 840w so i think that those things must be incorrect, can someone please help.

I want to keep the PSU as cheap as possible im not made of money!

tedstokes168

Also, could someone tell me what the expected power supply unit would be for the same spec mentioned above but with one ATI 2900 card and not 2

thx

DanGerMus

Those 2900 xt are extremely power hungry cards and with two you will need a good 800 watts if not more. And i cant stress enough that that PSU must be a good one. Seasonic ,tagan or enermax to name a few. You should not keep the PSU as cheap as possible it's a bad idea you get what you pay for and if you're dumping that much on your gfx then 150-200 isnt that much of a stretch.

Khannie

There is a PSU calculator in the useful websites sticky in the comp forum. It's really good. Scroll to the bottom of the list.

Chosen

Seasonic S12 600W or 700W. The Seasonics are rated based on their maximum continuous performance, unlike other brands that state their PSU's peak performance

They also happen to be some of the most silent ones.

christophicus

happygandalf wrote:

Those 2900 xt are extremely power hungry cards and with two you will need a good 800 watts if not more. And i cant stress enough that that PSU must be a good one. Seasonic ,tagan or enermax to name a few. You should not keep the PSU as cheap as possible it's a bad idea you get what you pay for and if you're dumping that much on your gfx then 150-200 isnt that much of a stretch.

I agree 110% with this post.

DirkVoodoo

Seasonics also have excellent efficiency ratings, better for your ESB bill and heat output.

Any reason you want to go AM2? If you are starting from scratch why not go intel/8800 GTX for ultimate performance.

Oh, and never ever put the words "ultimate gaming PC" and "keep the PSU as cheap as possible" in the same sentence, it is akin to "I want the fastest rocket-car on earth but I don't want to pay alot of money for good brakes".

Spend that cash on a good PSU children!!!!

Cuddlesworth

happygandalf wrote:

Those 2900 xt are extremely power hungry cards and with two you will need a good 800 watts if not more. And i cant stress enough that that PSU must be a good one. Seasonic ,tagan or enermax to name a few. You should not keep the PSU as cheap as possible it's a bad idea you get what you pay for and if you're dumping that much on your gfx then 150-200 isnt that much of a stretch.

Mine seems to be running fine, 6 hard-drives, a vapochill unit, 6120 yet to be oc'd and 2 gigs of ram. This is on a 620watt psu. I think you are scaremongering by saying it needs 800watts or more. Anything over 600 should handle it easy.

Anti

krazy_8s wrote:

Mine seems to be running fine, 6 hard-drives, a vapochill unit, 6120 yet to be oc'd and 2 gigs of ram. This is on a 620watt psu. I think you are scaremongering by saying it needs 800watts or more. Anything over 600 should handle it easy.

I have seen reports that the 2900xt will draw over 300W at full load. Which is a bit high. But even with 6hdds going non stop thats only 160W. cpu <100w depending on which one. So there is still overhead left over on a 600w.

I think its a way for these psu makers to get people to upgrade to a huge psu. Which will cost you more at the end of the month on your esb bill.

I have a 580W psu and it does mroe then enough.

Chosen

So you are telling me that the two 2900's and an AM2 dual core will need more power than my QX6700 quad core needed at 4GHz with two 8800's in SLI?

Cause it was running like this with a 600W Seasonic for 5-6 months and I didn't have any issues at all. But nevertheless, good thing you told me, cause now I can go and chuck the big money for an 800W power supply that my system absolutely needs...


:rolleyes:

DemonOfTheFall

Yes, the 2 HD2900s will need more power than than the 2 8800s. A fair bit more. They're the most power hungry cards *ever* and their power requirements rise steeply as you overclock or if your case is warm. Whatever chip ATI have used in the 2900 is an absolute pig.

Normally I'd be 100% against over speccing PSU's, since I see them as the most pointless of all e-penis things, but the HardOCP review clearly showed that you gotta take the requirements seriously

http://enthusiast.hardocp.com/article.html?art=MTM0MSwxLCxoZW50aHVzaWFzdA
.

They had a system with, either a 600 or 750 watt supply that ran SLI 8800s with no sweat, wouldn't work at all with Crossfired HD2900s

netman

According to this a system like that with 2 HDDs and two optical drives would draw about 540W.

Mind you its figures are quite conservative. As OCers have shown, a system with 8800GTX and E6600 overclocked to the hilt is supposed to draw 388W and in reality it's somewhere between 209W and 320W.
http://www.overclockers.com/articles1452/

I'm guessing you'd be safe with a decent 400W power supply.
If you wanted to play it safe, any decent 500-600W power supply would definitely do.
(ie decent being something proven to provide that much power, not a 10-euro power supply with a 1000W label on it)