GTX 680 2x8 pin safe?

Discussion in 'Mac Pro' started by ilikewhey, Aug 4, 2015.

  1. ilikewhey macrumors 6502

    Joined:
    May 14, 2014
    #1
    wondering if the gtx 680 classified is a safe route for my mac pro. i only ask cause the classified has 2x8 instead of 2x6. would i run into problems later on?
     
  2. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #2
    I terms of the spec, 8 pin can draw up to 150W, which is 200% of the 6pin's limit.

    However, in reality, unless the card only draw all the required power from one cable and almost zero from the others, it should not cause any problem. From all the reviews, I don't think the card will draw anything close to that 150W limit from a single line. It may draw a bit more than 75W via a single 6pin, but it's not gonna to hurt. Many guys (including myself) already prove that the card can draw more than 100W from a single 6pin without any problem. If it's too high, the Mac will shut itself down (the highest I did was around 110W from a single 6pin supply, no shut down, and didn't damage anything).

    I personally won't recommend anyone to use that 6 to 8 pin adaptor on the cMP. However, I really don't think that's going to damage anything.
     
  3. ilikewhey thread starter macrumors 6502

    Joined:
    May 14, 2014
    #3
    idk if it was a 6 and a 8 i would bit, but its 2x8 pins, i think i'm gonna be safe rather than sorry and on a the look out for a regular gtx 680 thn.
     
  4. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #4
    It makes no difference. The problem is a single 6pin line should not supply a 8pin input, but not the PSU is not powerful enough.

    So, 6+8 or 8+8 doesn't matter, as long as you don't want to go over that limit, do not use any 6 to 8 adaptor. On the other hand, if you are OK for that, the PSU is rated up to 980W, can easily supply 2x8pin without any trouble. In fact, 8+8 may be better than 6+8, because the card should able to draw power more evenly via the 2 booster cables, but not heavily rely on a single 6pin supply (which is what you want to avoid).

    That 6+8 or 8+8 has nothing to do with the card's real overall power consumption. Of course, technically a 8+8 card can draw up to 375W. However, the real peak consumption of the card you've mention is just about 250W from the review, not even close to that limit. It's just exactly the same as our Mac Pro can technically draw up to 980W of power, but I never heard anyone can achieve that.
     
  5. ilikewhey thread starter macrumors 6502

    Joined:
    May 14, 2014
    #5
    ok, if thats the case i'll go for a regular gtx 680 which is a 6+6.
     
  6. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #6
    I don't think any 680 can draw the sort of power to worry about.

    Those dual 8 pins are sort of like a 4 cylinder car with big dual exhaust tips.
     

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