How to upgrade graphics card (gtx 770 or 980) on Mac Pro 3.1 (2008)?

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How to upgrade graphics card (gtx 770 or 980) on Mac Pro 3.1 (2008)?

Hey,

I'm looking to upgrade my graphics card on my Mac Pro 3.1 - I've currently got a GTX 660ti but I was looking to upgrade either to a GTX 770 or if possible GTX980.

I have a few questions (GTX 770):

Power Requirement: I found a tutorial but I'm still unsure if the GTX 770 will draw too much power from the PSU? Its TDU is 230w and there is a lot of chat online about not going above 225w. I also noticed that my the 3.1 mac pro is about 980w - so I'm confused as to why the limit of 225w was mentioned (something to do with the power being driven from the pci slots?)
Cabling : The gtx 770 has 1x 6 pin and 1x 8 pin connectors. What/how should I connect to these pins? The tutorial mentions purchasing a 2x 6pin Y connector. Is someone able to confirm this?
Experience: Are there confirmed cases of the 770 GTX working on a mac pro 3.1 ?

Finally - I'm asking about a 770GTX since I have it. What is the best card (for gaming) that has confirmed cases of working with the 2008 3.1 mac pro?

Any help is much appreciated and thanks in advance,

OS X El Capitan (10.11.3), null

Posted on Feb 10, 2016 3:37 AM

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Answer 1

Best reply

lllaass

Level 10

210,411 points

Feb 11, 2016 4:28 AM in response to K-Jack222

The PCle slot supplies max of 75 watts. Each of the two AUX connectors on the logic board each supply max of 75 watts.

Thus you can get 225 watts which to me is close enough to 230 watts.

Others have successfully used the 770

Mac Pro 3.1 (early 2008) New Graphics Card, What are the options?

http://www.tonymacx86.com/general-hardware-discussion/115429-gtx-770-mac-pro-ear ly-2008-a.html

Here is for 4.1, basically the same as the 3.1 as far as graphics is concerned

https://stephenmonro.wordpress.com/2014/03/27/time-to-upgrade-the-mac-pro-41-200 9-with-a-gtx-770-pc-card/

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Answer 2

Feb 11, 2016 4:15 AM in response to K-Jack222

As Illaass says the difference between 225w and 230w is so small as to not be worth worrying about. To connect the power to this GTX-770 card you will need the following.

2 x 6-pin (Apple) to 6-pin (standard) cable - http://www.amazon.com/JacobsParts-Express-6-pin-PCI-e-Video/dp/B00OSLGBIC/

1 x 6-pin (standard) to 8-pin (standard) adapter - http://www.amazon.com/Tenext-Female-Express-Adapter-Fulfilled/dp/B0192SXFLG/

Alternatively you could get

1 x 6-pin (Apple) to 6-pin (standard) cable - http://www.amazon.com/JacobsParts-Express-6-pin-PCI-e-Video/dp/B00OSLGBIC/

1 x 6-pin (Apple) to 8-pin (standard) cable - http://www.amazon.com/JacobsParts-Express-6-pin-8-pin-PCI-e/dp/B00OSLGQGE/

Note: Apple use a non-standard 'mini' PCI power connector on the Mac Pro logic board - hence the need for special cables.

According to MacVidCards the GTX-770 is the highest recommended video card for a Mac Pro 3,1 model. However if you had a Mac Pro 5,1 then there are better cards e.g. the GTX-980Ti. See http://www.macvidcards.com/store/c1/Featured_Products.html

This does not mean that better cards like the GTX-980Ti will not work in a Mac Pro 3,1 - they will, it is just that other parts of a Mac Pro 3,1 will become the bottleneck and limit how much use you can get out of more expensive cards.

Note: If you buy a card from MacVidCards it will include any needed power cables.

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Answer 3

K-Jack222 Author

Level 1

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Feb 11, 2016 4:28 AM in response to John Lockwood

Thanks llaass & John Lockwood,

John, I noticed that my mac has 2x 6pin connectors so I initially thought of just purchasing the 6 to 8 pin connector. Do I need the 6 pin to 6 pin connector? I presume I can't just connect the 6 pin cable directly into the 6 pin connector on the 770?

Cheers,

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Answer 4

Feb 11, 2016 4:38 AM in response to K-Jack222

As I mentioned Apple use a special mini PCI power connector on the Mac Pro logic board. The standard PCI power lead that would be included with a video card being sold to PC users would therefore not fit.

Therefore the special 6-pin (Apple) to 6-pin (standard) cable will go from the Mac Pro logic board to the 6-pin socket on the video card.

If you already have one or more of these special Apple cables you can re-use it like I did when upgrading my video card.

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