Blender Renderfarm: Support von Blender GPU Cycles rendering

GPU rendering Blender Cycles vs. CPU rendering Blender cycles
Setup:
Blender 2.70, resolution: 1500x700px, 1000 samples

Rendertime:
Single core I7 3770K: 1h:16m:14s, price: 0,59$
Dual core Xeon 2650: 0h:32m:33s, price: 0,62$
Dual Tesla K20x: 0h:10m:46s, price: 1,02$

The dual GPU rendering system is 7.1 times faster than single CPU system with an I7 3770K and 3.0 faster than the dual Xeon 2650 system.