My new machine now exports a 20-minute XDCAM EX HQ timeline (with no effects applied) in Blu-ray MPEG2 HQ in 3m 54sec and an hour-long DV timeline (also with no effects applied) in MPEG2-DVD HQ in 2m 28sec. Wow!
Also, I rendered an 30-sec effects heavy animation in 2m 17 sec. A 12-core MACPRO costing 4 times as much took 2m 50 sec to render the same animation.
The new specs:
MB: Asus P9X79 WS
RAM: 64 GB
CPU: i7 3960X
GPU: the same Quadro 5000 as before
OSHDD: Corsair Force GT
Win 7 Ultimate 64
Case: Lian Li PC-V2120X
PS: Cooler Master ilent Pro 1200 W