Is it possible a 7850 crossfire on a 500w psu?

Megam

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Jan 3, 2013
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Hi! :D i was thinking of buying another 7850 for my baby :sol: the problem is that i have a cooler master GX Lite 500 w and i don't think it can handle 2 7850's along with my cpu,ecc. i put my config with the 2 7850 as well, on a psu calculator (http://www.extreme.outervision.com/PSUEngine) and it said that the minimum wattage required is 376 w and the recommended 426 W @100% peek load . so, do you is it possible run 2 7850 crossfire on my psu?
Here are my other pc specs:
Intel i5 3570k OC'd @ 4 GHz
Asrock z77 pro4-M
4GB DDR3 @1333 MHz RAM
1 HDD SATA @7200 rpm
1 DVDRW/CDRW Drive

Thanks and sorry for my bad english lol :ange:
 

yamahahornist

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Feb 1, 2012
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It might be able to! It will be pushing it to the limits pretty dang far. You will not be able to over clock them btw. The problem is your power supplies 12v rail only puts off 432 watts! So 426 WILL be pushing it. I recommend getting a 600 watt corsair, there like $66. Then w8 for the new 7870. You can try to run it but it may crash.

If you do get the new card download this: http://www.ocbase.com/
And run the psu stress test; that will tell you if you ok!

Good Luck!
 

bucknutty

Distinguished
The 7850 is a 130 watt part. x2
the 3570k is a 77 watt part
So thats 337 watts
Add in 50 watts for board ram, drives and fans and you have a max draw of around 390-400 watts.

I think you will be ok but with your overclock your cutting it close.
 

Megam

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Jan 3, 2013
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Lol :lol:
Well, i think i'll wait to get more money and i will buy a better PSU, maybe a 600w one.
Thanks :D
 


Actually, a standard speed Radeon HD 7850 draws peak power of 96w and maximum power of 101w. The i5-3570k will draw more power than 77w when OC'ed. Probably around 85w @ 4.0GHz. I estimate max power consumption on the +12v rail (since most of the power is drawn from there) as follows:

Radeon HD 7850 XFired = 202w
i5-3570k @ 4.0GHz = 85w
1 HDD = 12v
1 DVD / Blu-Ray Drive = 12w
1 120mm Case Fan = 12w
1 120mm CPU Fan = 12w

Estimated Total = 335w or 27.92 amps.

I prefer not to go above 80% of the maximum power the PSU can provide on the +12v rail. Therefore, if the PSU can provide at least 420w or 35 amps on the +12v rail(s), then technically you should be fine. Not sure about the build quality of the cooler master GX Lite 500 which does play an important role regarding a PSU's reliability and actual power output.

- RAM draws power from the 3.3v rail.
- The motherboard draws power from both 5v and 3.3v rails.
- Hard drives and optical drives draw power from the 12v and 5v rails.
- Total power drawn from the 12v, 5v, 3.3v rails cannot exceed 500w.