Enough power for crossfire

Discussion in 'Power Supplies' started by Moe747, Dec 25, 2012.

  1. Moe747

    Moe747 Junior Member

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    Right, so I'm buying a second 5850 tomorrow to crossfire with my current one, I have Corsair VX550w PSU. I know I'm really pushing the limits here but would it still work? I just want a second opinion. I have a couple case fans, an i5 750, Gigabyte P55m Ud4, 8gb ddr3 ram, 500gb caviar black hdd.
     
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  3. lehtv

    lehtv Lifer

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    I strongly recommend against a second 5850. That card is two generations old, almost three. Problems with this:

    VRAM. 5850 only has 1GB of VRAM, with Crossfire you are still limited to 1GB due to VRAM mirroring.

    Crossfire issues. Crossfire isn't always problem free - you may notice microstuttering, not all games support Crossfire, and framerate scaling isn't perfect even in games where Crossfire works well; it's only around an 80-90% bump in average framerates but framerates aren't as stable, with less increase in minimums. Single GPU is always preferable to dual GPU unless there is no single GPU to match the performance.

    Power consumption. Increased power consumption per performance isn't a good thing even with a strong PSU. Yours isn't, I'd want at least 650W for 5850 Crossfire with CPU overclocking. In your case, CPU overclocking will be required to minimize the bottle neck, and this increases power consumption further.

    Heat and noise. Dual card solutions will always be noisier and hotter than comparably powerful single GPU solutions, especially on a motherboard with no spacing between dual slot cards.

    Value. Your own 5850 is losing value fast, the sooner you sell it and upgrade to a faster single GPU, the better. At this moment you should be able to get around $75-100 for it.

    I'd recommend an upgrade to 7950 3GB with overclocking. Your PSU is easily enough for that and it will actually outperform 5850 Crossfire quite handily. The extra VRAM is a nice bonus.

    Is your CPU overclocked already?
    What's your gaming resolution?
    What's your case?
    Do you have a budget?
    Are you buying in the US?
     
    #2 lehtv, Dec 26, 2012
    Last edited: Dec 26, 2012
  4. philipma1957

    philipma1957 Golden Member

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    TO OP right now the hd5850 used on ebay runs 100 to 140, these are for cards that people claim are good.

    If you sell on ebay and clear 90 then buy a hd7950 for 300 you pay a total of 210.

    If you buy a new 5850 it will run you 200 on ebay there is one for 190 at amazon. my point is buying the hd7950 is smarter and your psu will run it.

    this is well like hd7950

    http://www.amazon.com/MSI-R7950-TWIN...rds=msi+hd7950


    http://www.superbiiz.com/detail.php?name=MSI-7950TF
     
  5. Moe747

    Moe747 Junior Member

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    I ended up not getting it, thanks guys. Thank you as well on recommending the 7XXX series, I haven't really experimented with crossfire/SLI so I don't know the repercussions of it. So I'll probably end up getting a 7950, since it can play Battlefield 3 at ultra settings with a good FPS. 1680x1050 monitor btw.
     
  6. lehtv

    lehtv Lifer

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    BF3 will especially require CPU overclocking assuming you play 64-player Conquest. Is yours overclocked at all?