Yeah that old 6 core cpu is quite effective, and can be overclocked quite easily, I have run it at 4.0 Ghz for some time but it made some more noise because it made some more heat, so i turned it down, so the cooling is more quieter.

I also use it for 3D graphics and after effects, and it rocks.

With Newest version of R8, stops playback after 1:03:569

CPU usage limit set in Reason 8 = 95%
Sample rate = 44,100 Hz
Buffer length = 1024 samples (max )

Hardware: 
CPU i7 3930K @ 3.2 Ghz Turbo mode 3.6 Ghz
RAM 16 GB running in Quad channel 1600 Mhz, CL9
Bose companion 5 Soundcard