It would greatly help if you provide the following.
1. Which mac Po do you have ? Mac Pro flashed to 5,1
2. Which Mac OS are you using. High Sierra
3. the Maker's name of your card eg : Sapphire, MSI, HIS etc. Don't have one
4. The card's graphic's RAM size Eg HD 7970 = 3gb. Don't have one
5. Pictures of the cards's OUTPUT PORTS. Don't have one.
I was trying to figure out the tools I would need to flash one regardless of what type of card without having access to a pc. Since I posted in the Mac pro forum I thought I could be a little less specific, but being a forum about computers my mistake(s). Just modified my profile so that I will make this mistake a lot less