I have 2009 mac pro 2.2 ghz / 8core. I'm considering upgrade CPU to xeon x5690 - 3.46 ghz 6core x 2 ( then it will be 12 core total ) I wonder if I upgrade my CPU and GPU to GTX 970, how fast my mac pro will be compare to 2013 mac pro. My memory is 1066hz-48mb now. I'm even considering changing gpu to gtx titan x. It will be almost $ 2000. I'm not sure if it's worth it. I just want to use my mac pro 3-4 years more if I spend $ 2000. I read some reviews that upgraded to 3.46ghz mac pro is faster than 2013 mac pro. I wonder if it's ture. Please advise what would be best choice for me. Thank you.