OTOY Forums

Hey guys !
I've tried installing a gtx 980 ti gpu in addition of the gtx 680 that I had already installed on my macpro, I bought an external corsair psu and a jump starter so I don't have to use the kind of questionable paper clip trick to get it running.
When I turn the computer on, the external psu fan is doing a hell of noise (I have a similar psu on a regular pc and I never heard it being so loud), and the second gpu is not recognized (not on the active gpu lists in the systeme preference pannel).. The nvidia web drivers are up to date, what could I be missing ?

Hi,
better to wait for a feedback from an hw guru, but in my experience, this means that the GPU powered externally is not receiving the correct power
Have you double check all the connections, especially the 6pin + 8pin GPU connectors?
If yes, what about trying with the paper clip trick?
It's quite easy and it works pretty well:

ciao beppe

Thanks for the quick insight, Bepe, but I think the psu is not the issue here (Well not anymore)
On the second startup the psu started up normally, when I look at the cards they are both lights on with the fans spining so I guess the 980 gpu seems to be powered normally.
The only problem is that in the devices list the second card still doesn't show up, I've tried switching cards but there's still only one showing..

Ok, perfect, so now they are correctly powered, so it should be only a sw issue with nvidia display or CUDA drivers.
Have you already updated all the drivers?
What version of OsX do you have?
ciao beppe

I have the latest cuda and nvidia webdrivers installed with El capitan OS.
I noticed that the psu won't start when connected to the graphic card.. what kind of sorcellery in that ? (I swapped the psu with a new one and same deal: runs smoothly when running by itself but not when connected to the gpu so I guess it's not the power supply that is faulty..)