AMD Radeon R9 280X Graphics Card

Hello,

I received a R9 280X as a christmas present as an upgrade for my 2008 Mac Pro running 10.11.6 and after installing it I can't seem to get a signal from it, and when I plug a monitor into my old GPU I can see my screen and when I check the " About This mac" section only my old GPU is displayed.

I know that the card is getting power because when I power on the mac the the fans on the card start to turn, i know that it was purchased on amazon and heres the link for all the exact specs:

https://www.amazon.com/dp/B01010EE0U/?tag=macforums0e4-20

Has anyone had any similar issues or have any kind of remedies or should I just contact the seller and see about a replacement or refund?

Luckily I still have my old NVIDIA GT610 but I can't access the boot screens because it is not any kind of mac flashed.

Welcome to our forums.

I'm not a Mac Pro expert but it sounds like your new GPU is not getting enough power. Did you go thru the installation instructions, especially the part about installing the power booster for the card? If so, you could have a defective card.

See thats the thing there isn't any information on needing to add a power booster to power the card, the card even came with the two cables to plug from the GPU to the logic board of my mac pro.