I have 2009 8core 2.2ghz / 48mb / gtx 670 mac pro. I'm considering upgrade my graphic card. When I check other's post, it seems I can use 970 or 980 without any problem even though it's not flashed. Is it correct? I wonder if I can use titan x 12gb on my mac pro without flashing it like gtx 970/980. And, I don't know if it's worth spending $1000 on graphic card (GTX titan X). Because If I add some more, I can buy new desktop... I'm learning cinema 4d and upgrading is for game on boot camp. ( GTA5 / Witcher3 / Fallout 4...) Please advise what's the best choice for me. Thank you in advance.