SUCCESS: 2 GTX 970 4GB in 2-Way SLI- FULLY FUNCTIONING

[spudguy77]

I know there has been a lot of talk about running graphics cards in SLI in a hackintosh, specifically now that NVidia released their newest line of Maxwell cards. After purchasing 2 GTX 970's, I knew it would be a job to get SLI working, if at all. A thread was posted and I started there. I revieced several replies of suggestions, although I was in fairly uncharted territory so far. Since my cards are now running flawlessly (so far) in SLI, I felt that it there should be a post that outlined the steps that were taken to make these SLI'ed cards work. Note that all screenshots will be at the bottom, labeled with what they are. So, here we go...

This might benefit you IF:
1. OSX is laggy and slow, your cursor jumps around. (Or you get a lot when you're just moving your cursor)
2. The screen has waves of white bars that randomly sweep across the screen.
3. Graphics are not recognized in the System Information program (I.E. they say something like you have less than 20 MB of VRAM, and don't say the correct model)
4. Graphical performance with a new NVidia "Maxwell" card is very poor.

The Fix:
There are a few things that can help with this. First of all, you should take a look at tonymacx86's post about the new NVidia cards to accquire the latest graphics drivers. If that doesn't work, there are still a few things you can do.
1. Make sure you have the latest version of the NVidia web drivers.
2. Look in /Extra/org.chameleon/Boot.plist and add "kext-dev-mode=1 nvda_drv=1" (no quotes) into the Kernel Flags section.
3. Change IGPEnabler to no, and add "IGPEnabler=No" into the Kernel Flags section.
-Screenshot

Results:
1. OSX should work like normal.
2. Both graphics cards are recognized in System Information (appropriate name and VRAM).
3. Excellent graphical performance.
-Screenshot 1
-Screenshot 2

Additional help:
-Refer to this thread for any additional help. This was the thread that I originally created to get help on this subject. If your setup isn't working correctly with a new Maxwell 900 series card, check this post and that thread so see if any of these fixes will help. I myself am by no means a graphics expert or hackintosh expert in any way, but I can share with you all what I have learned from this experience.
-Original Thread

Lastly, a HUGE thank you goes out to the following members who have really helped me a lot on this.
1. cccip
2. rabbit74
3. Pieroman69

[Edit]
If System Information gives you a significantly slower CPU speed after you apply this fix, here are the steps to fix it:
1. Change IGPEnabler (the one not in the Kernel Flags section) to Yes.
2. Restart.
3. Change IGPEnabler (in the Kernel Flags section) to Yes.
4. Restart.
5. Check System Information. The CPU speed should be back to normal.

 

[applebirne]

Thanks

 

[jonisign]

Is this really SLI, or is it just two graphics cards running in the same system? Try running a benchmark with 1 plugged in and then with 2 plugged in... does performance actually change?

 

[macgaga]

hey,

just make a Bench please. 1 Card, 2 Cards ... so we know if its real SLI

 

[jonisign]

My feeling is that this is not SLI, but rather just two GTX 970s running in the same system. Could be cool for running 6 4K displays at 60 Hz (3 on each card), but probably will not couple graphics acceleration across GPUs.

 

[spudguy77]

I haven't been on in a while, but these cards are infact in SLI. I have a SLI bridge running between them and I know it is being recognized as SLI in Windows.


Edit: I'm terrified to take one of the cards out and do a benchmark, I don't think I'd ever be able to get it working again Also, full acceleration is enabled on both cards.

Buuuut, if you guys know a way to prove it's SLI please tell me and I'll try to get you some proof (other than removing a card because I'm too scared to take one out)

 

[Gordo74]

I haven't been on in a while, but these cards are infact in SLI. I have a SLI bridge running between them and I know it is being recognized as SLI in Windows.

In OSX, the bridge does not matter at all. The two cards are running independently from one another. However, this still provides a lot of horsepower in CUDA applications and the like which use the GPU to offload CPU cycles, as multiple GPUs can be used in this instance. In games and the like though, only one video card will be utilized.

 

[spudguy77]

Are there even any games (or software in general) on OSX that are programmed to take advantage of an SLI setup? If they are running together, it might not even help since I doubt any programmers or companies making software for OSX thought to include SLI support, since no Macs have it.

So even if this is being recognized and treated as SLI, there might not even be a way of utilizing the setup? Is this correct?

 

[Gordo74]

So even if this is being recognized and treated as SLI, there might not even be a way of utilizing the setup? Is this correct?

The two cards are being recognized, however, they are NOT treated as SLI. They are treated as two independent cards. Whichever card that there is a monitor with a 3D application on, that is the card that is driving that 3D application.

SLI is when two cards work together and draw independent lines/frames for each other on the same screen to (theoretically) double the 3D power. This does not happen on OSX.

The ONLY time more than one card is used is in OpenCL/CUDA processing, when the code uses all available GPUs for processing.

The good news is, you have two cards that are both independently, natively, recognized by OS X with the new Nvidia drivers. This saves you from having to change any hardware between Windows and OSX.

 

[r2tincan]

Has anyone got this build to work with a Thunderbolt card installed as well?