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Installing a second ATI Radeon HD 5870 into a MacPro (mid 2012)...

Installing a second ATI Radeon HD 5870 into a MacPro (mid 2012)....


Currently the MacPro has one ATI Radeon HD 5870.

The only two power connectors that I can see in the logic board (without removing the 1st card) are connected to the 1st card.

The 2nd card (bought from Apple) comes with another two cables to connect to the power connectors in the 2nd card.

Question:

Where to connect these 2nd pair of cables in the motherboard, if the only two existing connectors in the motherboard are feeding the 1st card?


Thanks

Mac Pro, OS X Mountain Lion (10.8.3), MacPro (mid-2012)

Posted on Apr 27, 2013 11:12 AM

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Posted on Apr 27, 2013 11:17 AM

You can't. You would need to find splitter connectors either for motherboard connectors or the GPU's connectors. Be aware that the power supplied to the slots may not be able to handle two 5870s. Also, note that having two cards only will allow you to connect additional monitors. They will not make for faster graphics.

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Apr 27, 2013 11:17 AM in response to Bazzical

You can't. You would need to find splitter connectors either for motherboard connectors or the GPU's connectors. Be aware that the power supplied to the slots may not be able to handle two 5870s. Also, note that having two cards only will allow you to connect additional monitors. They will not make for faster graphics.

Apr 27, 2013 11:24 AM in response to Bazzical

Send the 2nd one back.


Buy a more powerful 7950 or GTX 680, both come in Mac Edition.


Buy a 450W PSU for the optical bay and deal with how to route cables (it is messy) so you have more 6 and 8-pin power options.


Check http://www.barefeats.com for a number of recent tests of GPUs.


What were you expecting to gain? 4 displays? Cross-fire is non-existent in Mac OS and neither is SLI.

Apr 27, 2013 12:02 PM in response to Bazzical

You can get any-old converters from Mini DisplayPort to DVI and other interfaces if you want to run to off one card. If you think you might ever need three displays on the card, you need to use ACTIVE powered converters that can boost the signals up to better Voltage levels. Otherwise, any two work fine and the third one drops out.


For DVI up to 1920 wide, Single-Link DVI is fine. Over 1920 wide requires Dual-Link DVI connectors, cables, and (if needed) converters.

Apr 27, 2013 12:31 PM in response to The hatter

@Kappy & @Hatter...thank you for the fast response.


Yes, I checked the specs of the 5870....each one will consume a max of 188 watts "board power" as per AMD. So...it means 376 watts max for the two.

As per Apple specs: "300w combined maximun for all PCI Express slots"...that's the problem there.


Apparently the MacPro can support two 5770 but only one 5870 !!??

I double checked the MacPro (mid-2012) specs and Apple is offering systems with a maximun of two 5770 cards but only one 5870 card.


I'll continue checking, including Hatter's suggestion of the 7950 or GTX 680.

I'll come back later....

Installing a second ATI Radeon HD 5870 into a MacPro (mid 2012)...

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