While my desktop I7 920 does a good job I'm figuring on building a few boxes for rendering as time and finances allow.

Vue 8 Complete allows up to 5 PCs for network rendering so I thought I'd build a cheap PC and farm it as I can aford to.

So this is a bang for buck question, I was considering somthing built around a dual CPU motherboard with some cheap I7 quad cores.

or

Splurge and grab a server with four Xeon CPUs.

Anyone here with experiance regarding this or other suggestions?

I'm using a Dell Precision T7500 as a render cow node. The T7500 runs with xeon processors at 3.2 ghz and it is doing a great job at crunching out vue movie frames. I've noticed in the task manager that all cores work on the render tasks way up in the high 90 percent range so I think the more cpu cores you have the faster the image gets completed. Originally I tried 2 core 2 duo pcs running at 2.4 ghz and 1 I5 laptop.  Just the one T7500 curnches out more frames per hour than those 3 combined.

Also helps to have the render node connected to a fast network so you don't lose too much time in the long run as information is sent back and forth from the node to the render console pc.  Does not matter much for single pictures but when you render something like over 3,000 image frames with a slight delay of 5 seconds in transmission per image it adds up.

Thanks Zonkerman, I've been examining the CPU performance charts at Thomas Hardware but they only cover up to things like I7s and other games machine stuff, finding performance info in regards to the high end CPUs like Xeons is thin on the ground.

So getting an idea of the real difference in performance is a definate plus;)

The xeon rendercow I use has 2 xeon W5590 CPU processors @ 3.33hgz. It is running 64bit Windows 7. From what I'v seen the W5600 series is very good as well but costs a lot. Check out some of the below videos to see more information about Xeon based PCs.  The youtube one below even shows some benching with 3d rendering between the different types of xeon cpus:

See what Autodesk (makers of Maya and 3Ds Max) Say About Xeon 5600

http://www.max3dmodels.com/intel-xeon-5600-series-workstations-and-autodesk.html

Cool animated video on the Xeon 5600 CHIP Features

http://www.intel.com/products/workstation/processors/demo/demo.htm

Video comparison of how fast a 5600 renders compared to 5570 and 5400 series xeon

http://www.youtube.com/watch?v=lN0TywxuBCg

The 5600s look good but are way out of my price range, even a 6 core I7 is about $1300+ here (Australia) despite the the US & AU dollars being almost identicle in value.

Its all 4 core I7s I think as even a 4 core Xeon cpu costs about as much as a full I7 system.

Someones getting rich but it aint me!