Mac Pro 5,1 GPU Power Cable

Discussion in 'Mac Pro' started by AcesHigh87, Feb 15, 2018.

  1. AcesHigh87 macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #1
    Hi There,

    My company recently purchases a GTX 1070Ti to put in our transcoding computer. It doesn't draw more than the 2x 6pin connectors the mac pro has so we're good on power and the card did come with an adapter to get from dual 6pin to 8pin; great so far.

    Unfortunately I remembered on the drive in this morning that the computer only has 1 GPU power cable which was supplied with it's original card, therefore I need another one. I just wanted to check before I order anything whether or not the Mac Pro's use some kind of special cable. So far as I can tell it needs a Mini PCI-e cable which I'm guessing is not something I could find locally. Is this what I'm looking for to get the full job done without needing the adapter cable that came with the card?
     
  2. bsbeamer macrumors 68020

    Joined:
    Sep 19, 2012
    #2
    Does your GTX 1070Ti card have an 8-pin power port? (Not all are exactly the same design style.)

    If it does have 8-pin, YES that cable is correct. Can confirm the Apple Dual Mini PCI-E 6-Pin to Standard PCI-E 8-Pin Video Card Cable (CAB467) works perfectly with MacPro 5,1. Purchased this cable and using it with my GTX 1080 Founders Edition.

    https://www.moddiy.com/products/App...tandard-PCI%2dE-8%2dPin-Video-Card-Cable.html
     
  3. AcesHigh87 thread starter macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #3
    Yeah, it has 1x 8pin connector. I'll order that. Thanks :)
     
  4. MagicWok macrumors 6502a

    Joined:
    Mar 2, 2006
    Location:
    London
    #4
    I've ordered the same cable for my GTX 1060 that has an 8pin connector to go into my Mac Pro, just waiting for it to arrive.

    I do have a (single) mini 6pin > 8pin cable, though it's hard to find info concrete info so far about the total power draw - I have the Gigabyte G1 1060 6GB. Some online shopping sites I've found state a 175W requirement, though that sounds high even for a factory overclock and LEDs.

    I did find reviews that point to the 8pin port drawing around 100W and drawing around 30W from the slot, so I'll play it safe and wait. Patiently. Waiting. Still waiting... :)
     
  5. AcesHigh87 thread starter macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #5
    I know I'm good on power, just need the cable.

    6 pin connectors are 75W each + 75W from the PCI-E lane = 225W so any card under that can be powered from the internal connectors without issue. I think my max draw is somewhere around 217 or something. If you're looking at 175W you'll be more than fine.
     
  6. MagicWok, Feb 15, 2018
    Last edited: Feb 20, 2018

    MagicWok macrumors 6502a

    Joined:
    Mar 2, 2006
    Location:
    London
    #6
    So when I quoted the power requirements, I was more musing about my specific card than yours or indeed other cards.

    I realise my earlier post was a bit vague and rambling! FE 1060's have single 6pin and a TPD of 120W, mine so happens to have an 8pin instead - with reviews talking about the power draw split between the PCIe slot (~30W) and the 8pin (~100W) for my specific card, meaning I shouldn't really use my 6>8pin cable hence the wait.

    Not all cards equally split the total power draw equally or to the max of the slot/power connector specs.

    Either way, I've got the same cable on its way as the one you referenced so unless there's anything wrong to report back with mine - enjoy your 1070TI! :)
     
  7. flowrider macrumors 603

    flowrider

    Joined:
    Nov 23, 2012
    #7
    Way to much:

    https://www.ebay.com/sch/i.html?_fr...0&_nkw=dual+6+pin+to+8+pin+gpu+cable&_sacat=0

    Lou
     
  8. bsbeamer macrumors 68020

    Joined:
    Sep 19, 2012
    #8
    Maybe, but I picked up for $15 with free shipping and was there within a week to USA. Not that bad considering what everything else in this machine has cost...

    Not all of those cables listed in the link are dual MINI 6-pin to single 8-pin cables for the 5,1. Some may require the original two mini 6-Pin to 6-Pin GPU cables. If you have both of those cables (some do not) you could just use this adapter:
    https://www.ebay.com/itm/NVIDIA-Dua...A-card-power-cable-ORIGINAL-PART/262787801295

    Personally was having power issues with my machine (caused by an HDD drive) and eliminated using an adapter as part of the troubleshooting process. Was (probably) completely unrelated, but never went back to using it.
     
  9. MagicWok macrumors 6502a

    Joined:
    Mar 2, 2006
    Location:
    London
    #9
    Just in case anyone will find it useful to know in the future when thinking about ordering, I received and installed the cable from Moddiy into my Mac Pro 4,1>5,1, and everything works fine, I just need to think how to nicely route the 50cm length.

    As @bsbeamer mentioned, the fact it's mini 6pin plugs tends to make sourcing the cable either a little bit more tricky depending where you live and/or more expensive than "normal" pci-e cables.

    The quality of the cable is reassuring and my GTX 1060 (~175W) is happy.
     
  10. AcesHigh87 thread starter macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #10
    My 1070Ti's max draw is apparently only 180, thought it was higher, so if you are having no issues I would be amazed if I do. Just gotta wait it out for the cable to actually arrive so I can power the beast.

    Thanks for the update.
     
  11. MagicWok macrumors 6502a

    Joined:
    Mar 2, 2006
    Location:
    London
    #11
    If you're running a stock nVidia Founder's Edition, then it'll stick to the 180W TPD [Total Power Draw] (not to be confused with TDP which is Thermal Design Power for anyone reading). Since you only have 1x 8pin, looks like you should be fine! Enjoy.

    If someone has any other aftermarket card, the TPD can be higher, accounting for overclocks, LED, more fans and beefier cooling etc etc.

    For example, this 1070TI from EVGA has a total power draw of 235W (with two 8pins) so using two individual mini 6pin > 8 pin cables might well not be good enough in this specific case. Not all manufacturers explicitly state on their website the total power draw of their card somewhat unhelpfully, mixed in with the fact a single 8pin is rated to be able to draw up to 150W on it's own, though often doesn't.
     
  12. bsbeamer macrumors 68020

    Joined:
    Sep 19, 2012
    #12
    Further complicating the issue: some manufacturers only have added a second 6-pin or 8-pin port to the reference design to almost show off about how powerful their card is.

    The GTX 1080 Founders Edition (one 8-pin) likely will be the last GPU I'm buying for this 5,1 machine. Holding onto the GTX 680 Official Mac Edition (two 6-pin) in case I sell one day, or will swap in and use the GTX 1080 elsewhere. The 5,1 is great for a lot of things, but it's really showing its age with video post-production...
     
  13. AcesHigh87 thread starter macrumors 6502a

    AcesHigh87

    Joined:
    Jan 11, 2009
    Location:
    New Brunswick, Canada
    #13
    My card isn’t the founders edition, it’s a Zotac Mini 1070 Ti But the manufacturer’s site specifically says the Max power consumption is 180W so I should be more than fine. I specifically avoided giant cards with LED’s and such.

    I would have preferred a founder’s edition just for the looks tbh but pesky bitcoin miners have made GPU’s expensive and hard to come by so I wasn’t in a position to be picky haha
     
  14. MagicWok macrumors 6502a

    Joined:
    Mar 2, 2006
    Location:
    London
    #14
    Getting any card, even second hand, at anywhere close to RRP is an achievement in of itself right now. The whole situation sucks including DDR4 DRAM prices.
     

Share This Page

13 February 15, 2018