Dual GTX 680 4GB make my 2010 12-core Fly!

Ironjer said:

Hi

I just installed 2 PNY GTX 680 (Flashed with EFI ROM Mac) on OSX Working good but i can't run both on Windows 8.1 freezes startup with white screen anybody is running good 2 cards in 8.1?

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I have no idea, but for troubleshooting purposes I would check each card individually by booting up with just one card in the Mac Pro. If that works, then try booting up with just the other card. This will ensure both of the cards are okay by themselves with Windows.

ActionableMango said:

I have no idea, but for troubleshooting purposes I would check each card individually by booting up with just one card in the Mac Pro. If that works, then try booting up with just the other card. This will ensure both of the cards are okay by themselves with Windows.

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Both card working good individually in windows but not together i can't pass the startup menu.

Have you installed Hyper SLI or whatever latest version is?

MacVidCards said:

Have you installed Hyper SLI or whatever latest version is?

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i can't pass the efi screen it will freeze when i selected the bootcamp drive or dvd install.

UPDATE:

just flashed back 1 card to PC BIOS and now both working and boot to bootcamp.

anybody is running 2 mac edition (flashed is the same) in windows?

this is so sad 1 pc version won't run full speed pci-express with efi rom would be great

UPDATE 2

just flashed back with mac rom again.

clean installation Windows 7 won't install correctly the drivers when 1 is mac edition and 1 is pc edition.

for now i can't use bootcamp, i prefer 2 Card running equal as original mac and 0 problems with osx i will wait some solution.

MacVidCards said:

Have you installed Hyper SLI or whatever latest version is?

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Any idea bro?

Ironjer said:

Any idea bro?

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You still haven't answered the question.

And in my experience, problems like this frequently occur when Windows sends the display to a port on the card you AREN'T connected to.

So if you get grey boot screen on bottom 680 but it hangs there before going to Windows, try the other card to connect display to.

Also, how are you powering the 680s?

Ideally you get Windows all set up the way you like it with 1 card, then add the 2nd.

MacVidCards said:

... .

Ideally you get Windows all set up the way you like it with 1 card, then add the 2nd.

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Excellent advice. That how I set up all of my multi-GPU systems.

MacVidCards said:

You still haven't answered the question.

And in my experience, problems like this frequently occur when Windows sends the display to a port on the card you AREN'T connected to.

So if you get grey boot screen on bottom 680 but it hangs there before going to Windows, try the other card to connect display to.

Also, how are you powering the 680s?

Ideally you get Windows all set up the way you like it with 1 card, then add the 2nd.

Click to expand...

I connected some ports mixing (did try some combination) with both cards my TV HDTV (HDMI) and my Cinema Display (DisplayPort to Mini DisplayPort) and getting grey screen always in main display working good but only OSX pass the boot when i try to boot Windows will hangs immediately before

I use an ePower 450W Dedicated PowerSupply

http://www.newegg.com/Product/Product.aspx?Item=N82E16817101044&cm_re=epower-_-17-101-044-_-Product

Ok guys, I Found a solution insert a DVD Windows 8.1 Update 1 Installation reboot and press option key and select EFI Boot (DVD Installation) it will pass and image come to display

now you need play good with GPT partion in OSX with Disk Utility not MBR to install Windows with EFI Native.

I'm testing now Windows SLI is Activated with DifferentSLI Auto v1.1

basically you need to do a EFI native installation not using bootcamp

I assume the issue with BOOTCAMP boot is that each GPU has EFI and you know it uses Legacy BIOS Boot.

I will post my progress...


Sorry for my english again.

PSU: how to?

Okay, like a few posters here I'm using Octane on a 12-core Mac Pro, and using a single GTX 680 Mac Edition. I'd love to throw some more power at it, and the simplest solution seems to be an additional PSU/GPU.

If I get a 5.25" PSU off ebay or somewhere, is it easy enough to get up and running without making huge modifications to the Mac casing? (I don't mind making a few snips here and there.)

Do PSUs like the FSP Booster and ePower Juice need an additional box, or do they plug directly into the mains? (Also is the ePower unit the better of the two?)

And is it easy enough to get it to power on with the Mac itself?

I have looked at the guide here: https://forums.macrumors.com/threads/1076970/

And it seems doable, but a little assurance goes a long way! Thanks.