I am seeking graphics card recommendations for a 2009 Mac Pro with 5,1 firmware running El Capitan. Not sure If I will update to Sierra. I do no video or 3-d and have no plans to. I do music composition, audio recording and some Photoshop and Illustrator. Would a 5770 or 5870 be alright? I understand the pros and cons of a non-flashed Nvidia card. My budget is under $150 American.