what wottage psu will i need for this setup ??

beasty6

beasty6

beasty6

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hey guys,

ive decided im going to get a decent psu with my new build instead of using mu pants budget one lol

so its going to have to power these componets

intel core i5 760 (going to overclock it like hell :D )
MSI p55 gd-80
corsair dominator 2x2gb 1600mhz dual channel (going to be overclocked as well)
lancool dragon lore k62 (4 fans at stock but am going to mod for another fan in top 5.25 drive bays)
MSI HD 6870 1GB (will be overclock as well)
corsair h50
samsung f3 1TB HDD
creative sound blaster x-fi

well thats it i think maybe a ssd further down the line and i may go crossfire with the 6870's not sure yet tho

now for the psu i would like a full modular such as the corsair HX series
i was looking at the corsair HX650w as its only £100 and its a corsair also its all new modular unlink the antec :( but yeh anway will 650 be enough for this including all the overclocking and maybe crossfire ??? or shall i step it up to a 750w ???

cheers guys and thanks for the help
 
I would go for 800W+

A single 6870 uses 300W (I'm guessing) - two at 600W leaving 50W for everything else if you wanted to go for a 650W PSU.
I would leave 200-250W overhead for all other components after graphics.
 
so a corsair hx850 will be fine for all of this including the extra power needed for the overclocking ???

note: this psu will have to last me a few years at least
 
Should be fine :-) - The way components are being built these days is to reduce power consumption without limiting performance through smaller fabrication processes.
 
The maximum rated power draw of the 6870 is only 151W and this review (using an overclocked i7 920 system @ 3.33GHz) doesn't even break 500W when under full load.

The HX 650W is a good shout, it gives you plenty of headroom even with 6870CF and is generally a solid piece of kit.

However, if you are planning to buy all-new CPU and GPU, you may want to consider waiting until January 9th, as by then the next generation Intel "sandy bridge" CPUs and motherboards will be out, as well as the top-end AMD graphics cards (the 6900 series) which arrive in mid-December.
 
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cmndr andi, is this including 2 of the 6870's as well as all the overclocking power needed ???

cheers for the responses guys :)
 
i have just done the corsair power calculator and they suggested a 850w at least for a heavly overclocked i5 760 2 6870's overclocked and 2 hard drives
 
beasty6 said:
cmndr andi, is this including 2 of the 6870's as well as all the overclocking power needed ???

cheers for the responses guys :)
Click to expand...

Yes, the figure for the 6870CF in the "load power consumption" graphs uses these components:which includes the two GPUs, the overclocked i7 CPU (this CPU's power consumption is 130W, instead of 95W like that i5), x58 board, 3 DDR3 sticks and an SSD.

I generally wouldn't suggest using a PSU calculator that is offered by a PSU maker - as they are generally rather conservative (translation: tell you to buy a bigger/more expensive PSU than you need). I usually use this one, which is pretty accurate - but unfortunately it doesn't show 6870s yet. However, if you use two 4870s (TDP 160W) then the total power consumption (with a 3.6GHz overclock, 3 SATA HDDs, 1 DVD drive, 3 x 120mm case fans) is 497W and a recommended PSU capacity of 547W. Hence a good quality 650W PSU will be plenty.


coldfused said:
Ok so the IDLE power consumption is 162W from socket. 266W under load and 477W in crossfire mode.
Click to expand...

Sounds right - so long as you are talking about total system power usage.
 
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reflux said:
That would draw about 500w under load I believe.
Click to expand...
In all the reviews I've ever read, no single card setup has ever been pulling anywhere near 500W.

[edit: except a GTX480... @ 420w, which is insane.]
 
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FoxEye said:
Where in the sky did you pull this figure from?

In all the reviews I've ever read, no single card setup has ever been pulling anywhere near 500W.
Click to expand...

We're talking about CrossFire 6870s here, and I'm talking about overall system load. As for single card setups pulling that amount of power, the 4870X2 and 5970 both pull around 450w with a decent modern system.
 
OK, but a decent 650W PSU is still only going to be at 66% load with a 6870 CF setup.

I can't see the need to go any higher... especially because 650W seems to be the price/performance sweet spot. The 800W+ PSUs command a huge price premium.
 
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