It has been years that i wanted to upgrade my good ol Macpro and i can tell you that thing is a beast.
it's new specs is now a dual 3.46 ghz X5690 intel cpu "delidded " , 12 core with 64 gig of ram with a RX 580 graphics card 8 gig.
I had to delid the cpu for clearance with the heat sink as i didn't want to temper to much with the connections and sensors and all.
I also bought a delid tool for the cpu and that was garbage. "NOT RECOMMENDED" but i did mine on a Vise in my shop.
it worked perfectly well by being extra cautious not to damage the capacitor under the original heat sink
The only issue that i had "after reading and watching youtube videos about it" was that i had to upgrade my OSX to 10.13.x so the rx 580 could work. that card won't work under 10.10 or anything under 10.13.x. Once upgrade the OS? all went super nice.
Now if only i could find a way to play Unreal tournament 2004 under that 10.13.x. I miss playing that game
will soon buy some 4k monitor, but i am not in a rush for it.