Reasonable Power Supply Size?

Ok, I have decided to hold fire on changing my GPU until the DX11 cards come out. however am still going to go ahead and up my PSU so that I dont have to change it as well as the GPU at once. However I am wavering between 600&1000w in sizes, and do know what to go for. I would like to be able to take the futute version of the 4870X2 however are cards becoming more power hungry? I dont want to upgrade just to upgrade again in the future....

From reading reviews I am leading towards Corsair and Be Quiet units. By the way it doesnt take much for the Be Quiet calculator to bump the card up to a 1200W!

Ok....A Be Quiet! 1000W is £169, where as a Corsair 1000W is £189, would their be any performance difference between these two to justify the 20 quid?

What I do find interesting is that Corsair's power calc says I would only need a 850W to power 2x 4890's where as the Be Quiet! calc says I would need a 1200W....

Slight difference!?

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Originally Posted by djglenn

Ok, I have decided to hold fire on changing my GPU until the DX11 cards come out. however am still going to go ahead and up my PSU so that I dont have to change it as well as the GPU at once. However I am wavering between 600&1000w in sizes, and do know what to go for. I would like to be able to take the futute version of the 4870X2 however are cards becoming more power hungry?

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Not really. Single cards from ATI at least have kept in the same ballpark for a while, so the only big leaps are when they double the cards as in the X2. I would not expect a 5870x2 to consume a great deal more than a 4870x2.

While a very good 600W supply would be fine for that, I'd push towards 700/750 just to be safe and have a large margin for overclocked cards etc. No need to go further than that unless you're going to be running three or four cards.

I'd wait until you are ready to buy the graphics card. You never know if there will be new requirements re: connections etc... and in the mean time you won't gain anything (maybe even pay more on your electric bill depending on the efficiency of the PSU at the power draw you are taking from it)
Put the money to one side ;)

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Originally Posted by sjbuck

I'd wait until you are ready to buy the graphics card. You never know if there will be new requirements re: connections etc... and in the mean time you won't gain anything (maybe even pay more on your electric bill depending on the efficiency of the PSU at the power draw you are taking from it)
Put the money to one side ;)

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Probably sound enough advice, however I am giving my little bro my old system which has an unbranded cheap @ss psu in it, so would prefer to give it with my VX450W.

How likely is it that there will be new requirements or new connections come out in the new two years? Surely it that is the case it will be a matter of getting some form of adaptor to do the switch?

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Originally Posted by djglenn

How likely is it that there will be new requirements or new connections come out in the new two years? Surely it that is the case it will be a matter of getting some form of adaptor to do the switch?

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Yes exactly. Molex is still a very reliable standard and just about every change from that will come with some kind of molex adaptor. (I've got three in my case - Molex->PCI-E, Molex->Sata and Molex->3pin fan).

TBF I think your VX450W will cope fine. My system spec is similar to yours, except with half a dozen more HDDs attached. Power usage with everything maxed out is about 300-320W from the wall (equates to 255~270W). I think it should be fine with a X2 card unless you also want to stick an i7 into the system.

For whats its worth I bought a Corsair TX850W PSU, so that I could put my decent PSU into my lil bro's computer.

So far very happy with it, alot of cables but there is plenty of space in my Antec P182 case. I think it might be marginally louder than my VX450W, but it is very slight, and the only reason why I noticed is because I was listening for it.

Thanks for the help.

Also remember that optimal efficieny is at about half load on most PSU's.

I used a wall socket meter, and I was pulling around 90 to 110 watts for my machine. So I plan to decrease to a 450W PSU, even with a new graphics card, should mine go pop again.

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Originally Posted by Antagram

Also remember that optimal efficieny is at about half load on most PSU's.

I used a wall socket meter, and I was pulling around 90 to 110 watts for my machine. So I plan to decrease to a 450W PSU, even with a new graphics card, should mine go pop again.

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Actually no - max efficiency is at about 80% max load, although you will have to look at mfrs specs to see where the max efficiency is.

That said, most modern quality PSUs have fairly flat efficiency curves from about 50% loading to 90%, so it makes no sense to opt for a much bigger PSU than you really need.