Dual Graphics Cards

[RSN]

Hi all.

 

For those who want/need multiple video cards, my recent experience with several card could help

 

Mavericks 10.9 but I could swear its the same of ML and Lion

Mobo Intel Dx79to

ICore 7

16gb

Ssd 120 and 1tb hd

Video cards, the issue at hand.

 

My objective was to have 2 cards with 4 screen, 3 vga and one Hdmi. Thats two video cards.

All work was done on nvidia cards. Sorry ATI

 

So install an old gt 9500 along my gigabyte gtx 570 hd and boot. No such luck. Changed pcie slots, no go.

 

Ill make a very long story short and share theresults and possible logic.

 

Cards have to be of the same "family". By this I mean their internal architecture must be the same.

 

For instance the gt 9500 and the gtx 570 are different.

 

So why is this important? Because Osx will load only ONE controller to manage all cards (apparently). They can be many cards, but same family.

 

This is seen in the boot log in a message that states that, ex, "NVDANV50HAL loaded and registered", when a single card installed. If two cards of different family arch u can see that i loads both controllers but does not register them and hence u get two vga with no qe/ci on the second monitor in each card.

 

Ex. The gt9500 loads the NVDANV50HAL controller while the Gtx 570 loads the NVDAGF100HAL controller, individually. If u put both cards, it will at most load the PCI0 card with qe/ci but the second card just in vga, if it boots at all.

 

So, do not mix the card controller family, use same family. Ex, the gtx 570 and the gtx 620 are the same family NVDAGF100hal controller and will be qe/ci both cards and hence 4 monitors.

 

I had to REMOVE my dsdt and boot with chameleon 2266 GraphicsEnabler =y to get both cards, gtx570 and 620/440/220 to work. (Any combination of them)

 

Hope it helps.