Price/performance is why I'm writing this post. This Helmer render farm is over 6x faster per dollar than a Mac Pro at ray tracing in Cinema 4d. How? Well, the Mac Pro uses Intel Xeon chips. Xeons give you access to more than the 64GB cap of Intel Core i7 CPUs, and let you use ECC memory. While the ram helps if you're working on The Hobbit, most 3d artists never touch 16GB of RAM on a render. On top of that, the core clock goes down as the core count goes up. The 12 core Xeon in the 7000 dollar Mac Pro is clocked at 2.7GHZ (vs 3.4), with a max turbo freq of 3.5 (vs 3.9). This means that a 12 core CPU is not 2x as fast as a 6 core, and that single threaded operations that are common in the prep stages of a render are slowed down. Contrary to the beliefs of some, there's nothing inherently faster about Xeons. a 6 core i7 CPU is just as fast as a 6 core Xeon CPU.

The Mac Pro can edit video, play games, use the viewport, surf Facebook, do lots of stuff my farm can't, but it isn't a dedicated render machine. Dedicated nodes are becoming an absolute must for a full time 3d artist. If you can't work on a client's project because another client's shots are rendering on your machine, you're doing 3d wrong. YOUR WORKSTATION SHOULD NOT BE THE ONLY THING YOU RENDER ON. This is what irks me about the Mac Pro fetish. It's a fast box, but your workstation being all of your rendering resources is a recipe for disaster.

For those seeking out a better setup than they currently have, i say skip the Mac Pro entirely if you aren't married to OS X. For the cost of the $4000 6 core Mac Pro, you can build an equivalent 6 core Windows box AND a 16 core Helmer render box. That's 4 times the render power for the same price. The 6 core PC workstation above is as follows. I'll avoid prices as they fluctuate from place-to-place

Intel 4930k CPU

32GB of 1600 MHZ RAM (Vs Mac Pro's 16)

Asus p9x79 Motherboard with support for 64 GB of RAM

Thermaltake 700 watt PSU

2x 256GB ADATA SSDs in RAID 0 to neatly match the performance of the Mac Pro's blistering PCIe 'SSD

1 GTX 770 GPU with 2 or 4 GB of VRAM. This card beats the Mac Pro's underclocked FirePros in Cinema 4D's viewport benchmark

Cheap case

This build combined with a Helmer computer cluster will make your work much easier than having a single $4000 Mac Pro, as you can offload the work entirely to the farm, or just have it kick in to speed up your renders along with your workstation. If you do build one, i cannot stress airflow enough. I alternated the sides i placed the cooling fans on my nodes, in the name of sexy fashion. What i ended up with were 2 nodes where the fans blew directly over the CPU, and 2 where the fans blow right by the CPU, raising temps about 10C. Do not. Skimp. On. Airflow.