Which GTX 1080 TI FE and Power question on MP5,1

Discussion in 'Mac Pro' started by zayaso, Jun 26, 2017.

  1. zayaso macrumors member

    Sep 29, 2014
    Thank you forum members in advance for replying.
    Recently purchased myself a new 40 inch Samsung monitor to replace my old apple monitor and after reading here have concluded that I need a new GPU. Currently have a GTX 780 and AFAIK does not do 4K resolution (am I wrong?). Was looking at purchasing a GTX 1080 TI FE and need help choosing if possible:
    1. Newegg model:
    MSI GeForce GTX 1080 Ti FE DirectX 12 GTX 1080 Ti Founders Edition 11GB 352-Bit GDDR5X PCI Express 3.0 x16 HDCP Ready SLI Support Video Card

    2. Nvidia model:
    NVIDIA GeForce GTX 1080 Ti Founders Edition

    Experiences with MSI? Need a card pretty quick, so feedback would be great.

    Also power question: with my current 780GTX I added a 450W power supply system to my 5,1. Internally mounted where my 2nd CD player bay is. Do I need to add power to my machine? I have read that some people just add in the GTX 1080TI and it runs just fine but wanted to double check.

    My Machine:
    Sierra 10.12.5
    2x3.46 Ghz 6 core Xeon, 32 GB memory
    SSD drive for Apple OS
    SSD drive for Windows OS

    Thank you in advance!
    --- Post Merged, Jun 26, 2017 ---
    Or a different card?
    I do no video work- consider me a consumer user that does gaming, surfs the web, watches videos, and does document editing (word, powerpoint, etc).
  2. Prince134, Jun 26, 2017
    Last edited: Jun 26, 2017

    Prince134 macrumors 6502

    Aug 17, 2010
    1080 Ti FE are supposed to be all the same. They all originated from Nvidia except different boxes from vendors. If you don't have spinning HDDs, I have all SSDs for examples. You can have on board 2x 6 pin plus the EVGA power link (once sold only $9.99 in AMAZON) with your 1080 Ti. You should experience no issues. You don't need that 450W. The apple 980W PSU is more than enough to power single 1080 TI. With EVGA power link, you don't need power mod.
  3. Squuiid macrumors 65816


    Oct 31, 2006
    Can you clarify how the evga power link works?
  4. flowrider, Jun 26, 2017
    Last edited: Jun 26, 2017

    flowrider macrumors 603


    Nov 23, 2012
    Concerning power, you may want to read this blog at MVC:


    Personally I like Gigabyte 3 fan coolers (WindForce 3X). Some reviews have said the FE is not adequately cooled. My last three cards have been Gigabyte models. I have used MSI in the distant past with no issues. But, as has been said, all FEs are the same no matter the OEM.

  5. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
  6. Prince134, Jun 26, 2017
    Last edited: Jun 26, 2017

    Prince134 macrumors 6502

    Aug 17, 2010
    Basically it balanced the two 6 pins power draw, therefore won't trigger the power draw protection on board, which means safe for the board when balanced.

    Please read this thread:

    I have dissembled 2 EVGA power link and showed how it worked. Read only with photo and explanation on post #1 and #4 for the part with EVGA power link, if you are not going to mod your power supply.

    Here again, taking the chance to explain more detail. In this photo, on top you are free to put one 6 pin or 2X 6 pin, or 2x 8 pin, or singe 8 pin, or even only a pair of 12V+GND. It doesn't matter, yes, free for you. With Mac Pro 5.1, you of course put 2x 6pin.

    On the left, you can choose 1x 6pin, 2x6pin, 1x 8pin, 6+8 or whatever your card needs, for GTX 1080 Ti you need 6+8pin, which is included in the package. The connectors are on a rail which is just a 12V+GND.

    Screen Shot 2017-04-28 at 12.10.58 PM.png

    Now the magic things is that you screw your connectors (included in the EVGA power link) on the rail, pin counts (or readouts) are auto-configured.

    Screen Shot 2017-04-29 at 1.17.04 PM.png

    The following photo is irrelevant to the OP, just to show you how my two internal gtx 1080 ti working after soldering 12V + GND from the PSU. But, you get the idea when you put 2x6 pin to the EVGA POWER link, it draws both mini 6pin's power together on the rail for a single 1080 TI like OP wants to achieve.

    Screen Shot 2017-04-29 at 1.16.42 PM.png
  7. zayaso thread starter macrumors member

    Sep 29, 2014
    Thank you H9826790. Was unaware of the card specs until you mentioned it.
    I am trying to compare if the GTX 780 can perform at the same display specs as the GTX 1080TI.
    Looking at the Nvidia website, I can see the display specs as follows:
    GTX 1080TI - DP1.4, HDMI 2.0b, HDCP 2.2
    GTX 780- HDCP Yes, HDMI Yes.

    Are they at the same level?
  8. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
    Impossible, HDMI 2.0b release on 4 Sep 2013, but GTX 780 launch on 23rd May 2013.
  9. zayaso thread starter macrumors member

    Sep 29, 2014
    Thank you H9826790 for the prompt response!

    Can you help with my power question? Prince provided his answer, but I am not confident in modifying a power supply- Do I need an external PSU for a 1080 GTX TI? I have a 450 W one already installed; or can I use the two 6 pin connectors on the motherboard?
  10. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
    I personally tends to go Prince's route. HOWEVER, that's because I am happy to let the card draw more power than cMP's official limit.

    (I used to power two 7950 by internal power only. Each card supposed to be powered by 2x6pin. Therefore, technically I need 4x 6pin output. But I can fit them in with just 2x mini 6pin power source.)

    And what I found is very matching with Prince's theory. The key is how to balance the power draw.

    Each mini 6pin can deliver up to around 120W before shutdown protection kicks in. So, they can deliver about 240W in total. Plus the 75W from the PCie slot, it's way more than the 1080Ti need.

    However, if you did nothing to balance the power draw. The card will only draw up to 75W from the 6pin, and may draw >120W from the 8pin (which is rated up to 150W). That means, shelf shutdown occur.

    Since 75 (6pin) + 150 (8pin) = 225W max draw. And each mini 6pin can practically deliver up to 120W, which means 240W available in total.

    Therefore, as long as able to balance the power draw. I will say the shutdown protection should never be triggered.

    And the Powerlink he suggested is NOT a PSU mod, but just a bridge in between the mini 6 pins and the card's input. Therefore, all power will flow though the Powerlink, which make sure all loading will evenly distributed between the mini 6pins.

    However, if you are not happy to do that (draw more than the official limit, or anyway to balance the load). I will say Flowrider's link provided the best solution.

    2x SATA -> single 6pin
    2x mini 6pin -> single 8pin

    In this case, everything will be within official limit. However, you have to sacrifice 2 SATA ports.

    And if no more SATA ports avail on your cMP. The last resort if external PSU. IMO, it's more complicated than just add a Powerlink.
  11. zayaso thread starter macrumors member

    Sep 29, 2014
  12. Synchro3, Jul 28, 2018
    Last edited: Jul 28, 2018

    Synchro3 macrumors 68000


    Jan 12, 2014
    Thanks for the info.

    Because I had a broken board (not sure if it was the 0087 firmware, a failed SPI Flash or something other) I just installed an EVGA PowerLink to exclude all risks.

    With the power link installed the reference design graphics card has just enough space in the Mac Pro. A longer graphics card won't work.

    On the PowerLink I replaced an 8-pin with an 6-pin-connector, and I connected the normal Mac Pro Mini-6-pin cables to the PowerLink. All working fine so far.

    IMG_1514.jpg IMG_1515.jpg IMG_1519.jpg IMG_1520.jpg IMG_1522.jpg IMG_1537.jpg IMG_1542.jpg

    Update: The PCI fan is more responsive now:

  13. Spacedust macrumors 6502a

    May 24, 2009
    I was running Maxwell GTX Titan X for more than a year with just 2x6-pin without any adapter and worked great.

    For GTX 1080Ti I would recommend a config like this with 6-pin from SATA and standard 2x6-pin combined into 1x8-pin:

  14. AlexMaximus macrumors 6502a


    Aug 15, 2006
    A400M Base

    I can confirm that!

    My 980Ti never made problems, but I used to have a slight gellow artifact on my screen when the card was pushed hard. It disappeared completely after the installation of that power link. I highly recommend this power link for everyone with a power hungry Nvidia card.

  15. Speedstar, Dec 28, 2018
    Last edited: Dec 28, 2018

    Speedstar macrumors member


    Oct 10, 2008
    you already now my case well evga680mac 2x6pin 195 WMaximum, pnyQUADROk5000pc 1x6pin 122 Maximum
    evga bridge useful for me with 2x6pin ?

    1ST FROM MINI 6PIN TO -----DIRECTLY-------- 1x6 PINinto EVGA bridge then to GTX680,
    split Y --------- A -------- -Other one 6PIN to bridge 2nd6pin at GTX680
    ..................................... Y --------- B -------- -and only one 6PIN to k5000

  16. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
    If I understand correctly, you mean both mini 6pins connect to the EVGA PowerLink, then one output feed directly to the 680. The other output further split to the 680 and k5000, right?

    It should work.
  17. Speedstar macrumors member


    Oct 10, 2008
    understood evga beside in McP case as device not on card directly ... then i need 6 pin to 6 pin and y without mini pie-cables except 2 connected to vega bridge
  18. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong

    Two mini 6pin to 6pin (or 8pin) -> EVGA PowerLink -> both GPUs (normal connector, need one splitter)
  19. Speedstar, Dec 31, 2018
    Last edited: Dec 31, 2018

    Speedstar macrumors member


    Oct 10, 2008

    is there any adapter in the world that fits under the graphic card in blocked pci slot that can provide 75 watt ?

    you know 1slot taken by first gpu
    2nd and 3rd taken by 2nd gpu
    any chance to take 75 watt benth 2nd gpu from 3rd blocked not used slot
    molex to pcie 6 pin and go jonny go ...

    evga says it provides power to the bus I want opposite, I feel stupid

    Attached Files:

  20. h9826790 macrumors G4


    Apr 3, 2014
    Hong Kong
    Haven't see such adaptor yet.
  21. pidcin1 macrumors newbie


    May 14, 2018
    Hey, I am going to be upgrading my computer with a titan X, and I’ve been searching for info regarding powering it. I see that you have successfully run a GTX titan X with two 6 pins ? And didn’t have to do a 6 pin and 8 pin? Have you noticed any performance drops or any odd things ?
    Where did you get the other 6 pin adapter to draw from? I am new to all this.
  22. MIKX macrumors 6502a


    Dec 16, 2004
  23. bsbeamer macrumors 68000

    Sep 19, 2012
  24. startergo macrumors 6502a


    Sep 20, 2018
    That is bad .

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