Issues with GTX 1080 in Mac Pro 5.1

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Issues with GTX 1080 in Mac Pro 5.1

Hello everyone, I have a Mid-2010 Mac Pro running MacOS Sierra 12.10.5. I purchased an Nvidia GTX 1080 graphics card for 4k video editing and gaming via boot camp after reading about the release of the Pascal drivers for Mac OS. However, I have had intermittent response from the card. I'm powering the card from the pci-e slot (of course) and I'm using a dual mini 6 pin to 8pin cable so I should be getting 225w of power. Now, I have an SSD in bay one, and standard ssds in the other drive bays.

I'm about to do a clean install of Sierra and try again as it worked perfectly when I had a clean but has anyone had success with a similar set up to this?

Thanks for your time.

Mac Pro, macOS Sierra (10.12.5), 5.1 2.8ghz Quad Core. 16gb ram

Posted on Jul 1, 2017 8:03 PM

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Answer 1

Jul 3, 2017 1:15 PM in response to MannyGamazo

As far as I can see the power requirements for the typical GTX-1080 card are less than 200W e.g. 180W, this is well within the capabilities of the Mac via the PCIe slot at 75W plus the two 6pin connectors each also 75W totalling 225W.

However it also seems that most GTX-1080 cards have a single 8pin socket rather than two 6pin sockets. As such you would need to get an 8pin to two 6pin adapter. If you only plug a single 6pin in to the 8pin socket then it would only get the 75W from the PCIe slot plus 75W from the 6pin cable making only a total of 150W which would be to little.

I think something like this Amazon.com: GutsParker Micro Dual 6-Pin Female to 8-Pin Male Cable: Home Audio & Theater is what you may need.

Note: The GTX-1080Ti needs more power and might it seems exceed the standard power capabilities of the classic Mac Pro meaning you might need to use an external or secondary power supply. Have you mixed up the 1080 and 1080Ti?

You will also need the correct version of the Nvidia drivers for Sierra 10.12.5 which is currently http://www.nvidia.com/download/driverResults.aspx/119315/en-us

In terms of someone who seems to have had some success with both the GTX-1080 and the GTX-1080Ti see http://barefeats.com/cmp_pascal.html however MacVidCards have reported power problems with the 1080Ti.

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Answer 2

MannyGamazo Author

Level 1

10 points

Jul 3, 2017 1:20 PM in response to John Lockwood

I had figured I did have emough power. I'm just running a GTX 1080, not a 1080ti.

I bought a dual 6 pin to 8pin adapter and two mini 6pin to 6pin cables.

I guess I did not realize that I would still not have a boot screen with the GTX 1080. even with the updated drivers I'm just going to buy a stock graphics card (the small Nvidia card that takes up 1 pci-slot) as back up.

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