power supply for 2 sapphire r9 280x

[Elementxyz]

i am making a build therefore i wanna know
how much power supply is enough for 2 way crossfire of sapphire r9 280x
the official site recommend 1000w but i want to be sure

also my build
intel i7 4770k
corsair 500r
corsair vengeance 1600 ram 2X8gb
corasir h100i
MSI Z87-G43 motherboard
1tb wd black
samsung 120gb evo pro ssd

i will be overclocking as much as possible also right now i am gonna buy only 1 sapphire r9 280x but i want psu to be enough for 2 280x

 

[Jake Wenta]

250w TDP x2=500w
+ you cpu and all other components such as peripherals, fans, hdd...etc.
guessing ~700w-750w with OC. So a platinum maybe gold rated 850w+ or 900w+ gold or 1000w+ bronze.
CPU wattage=TDP*(OC Mhz/Stock Mhz)*[(OC Voltage/Stock Voltage)^2]
84w TDP on CPU -~125w OC.

 

[Elementxyz]

what does this means

CPU wattage=TDP*(OC Mhz/Stock Mhz)*[(OC Voltage/Stock Voltage)^2]
84w TDP on CPU -~125w OC.
Explain please

 

[iam2thecrowe]

would be better off with a faster single card like a 290/290x. then you remove the hassle of crossfire and all its problems.

 

[Jake Wenta]

what does this means

CPU wattage=TDP*(OC Mhz/Stock Mhz)*[(OC Voltage/Stock Voltage)^2]
84w TDP on CPU -~125w OC.
Explain please

I agree with lam as well about getting a single card, such as the 290 or 290x.

And that is an algorithm for finding out how much wattage your CPU will require if you were to overclock it.
TDP=Thermal Design Power
Stock, the CPU is 84 watts.

 

[alexr9]

A good power for 2x r9 280x is minimum 900W, i recommend you a 1000W psu and not buying saphire version unless you get the vapor x.The best one is gigabyte version.
And reading the last answers, i have to say that r9 290x is a bad option because the perfomance is not getting far comparing with 280x. Other options would be 7990 and 780ti. But when good drivers come out, then the power of 280x crossfire will be amazing.

 

[Jake Wenta]

A good power for 2x r9 280x is minimum 900W, i recommend you a 1000W psu and not buying saphire version unless you get the vapor x.The best one is gigabyte version.
And reading the last answers, i have to say that r9 290x is a bad option because the perfomance is not getting far comparing with 280x. Other options would be 7990 and 780ti. But when good drivers come out, then the power of 280x crossfire will be amazing.

What?
Fist off, the 290x out performs the 280x by quiet a bit, and it is an all new GPU with trueaudio and different hardware. A 280x only has mantle capability-but it is a rebranded 7950.
Also, a 7990 is not worth the money, and it is two GPU's on one card, so it is pretty much xfire.

And a 780ti is a single gpu, but the card is 700 dollars, while it compete with the R9 290x for 550 dollars. The R9 290 is close to the 290x, but this is because of the heat throttling the card, but you can install this to fix that issue:
http://www.tomshardware.com/reviews/r9-290-accelero-xtreme-290,3671.html

Once more people start coming with aftermarket coolers and other cooling solutions, you'll see the R9 290x really do as well as a 780ti.

As for a PSU-I've stated it in a previous post.

 

[alexr9]

A good power for 2x r9 280x is minimum 900W, i recommend you a 1000W psu and not buying saphire version unless you get the vapor x.The best one is gigabyte version.
And reading the last answers, i have to say that r9 290x is a bad option because the perfomance is not getting far comparing with 280x. Other options would be 7990 and 780ti. But when good drivers come out, then the power of 280x crossfire will be amazing.

What?
Fist off, the 290x out performs the 280x by quiet a bit, and it is an all new GPU with trueaudio and different hardware. A 280x only has mantle capability-but it is a rebranded 7950.
Also, a 7990 is not worth the money, and it is two GPU's on one card, so it is pretty much xfire.

And a 780ti is a single gpu, but the card is 700 dollars, while it compete with the R9 290x for 550 dollars. The R9 290 is close to the 290x, but this is because of the heat throttling the card, but you can install this to fix that issue:
http://www.tomshardware.com/reviews/r9-290-accelero-xtreme-290,3671.html

Once more people start coming with aftermarket coolers and other cooling solutions, you'll see the R9 290x really do as well as a 780ti.

As for a PSU-I've stated it in a previous post.

Sorry for not being more detailed:
In spain the price between r9 290x and hd 7990 is about 20€ (about 30$) so perfomance/price, hd 7990 is much better, 780ti is 100€(about 160$) more expensive than a 7990 but is the most powerfull gpu at this moment.
And sorry but you can not compare an r9 280x with a hd 7950 when the perfomance is more or less the perfomance of 7970ghz edition.
So price/perfomance r9 280x is the best now in the market.
And r9 290x will not perfome like a 780ti.

 

[Jake Wenta]

The 7990 is more powerful as a card simply because it is two GPU's on one card. But you can't compare it to a 780ti, but rather a 690.
And I concur about that statement, I'd say a R9 290 (400 dollars) is the best price to performance as of right now.

 

[SteveJo]

I disagree with the post about getting one single 290x vs 2-280x cards. 2 280x cards in xfire will by far perform better than a single 290x even though the 290x is a very nice card its just a fact, yes you will need more power but there is a reason you will need more power its because you will get more performance.

 

[Jake Wenta]

Dont post in a solved thread please. And you're wrong, simply because the 280x has lower memory bandwidth so on higher resolutions it wont perform as well. Also it will use a lot more power. On top of that, it is a rebranded GPU pushed to its limits, where as the 290 non x is a new GP ith overclocking ability. when this post was made, the 280x was 350 and the 290 was 400, and now due to litecoin users. they bought out amd cards and the prices rose.
Regardless, you will only see slight improvement with 2 280x cards over the 290 let alone a cooled 290x. Another thing you haven't considered is gaming. Some games do not support dual GPU while other perform worse or just not all that great with it. BF4 crashes when using it, and a lot of new released ames need patched for xfire or SLI to function properly.

700 dollars for (900 now) ~90 fps and possible microstuttering and maybe future driver issues. Vs 400 (now 500) for 290 (not 290x)for ~80FPS and 500wattage vs 275 wattage.
I mean the clear choice would be the 290 or the 290x. And you can always crossfire them and get Kraken G10 and Kraken x40 and overclock them