I’ve read the link on GPUs and find (I think…) that the Nvidia quadro 4000 is supported, however I don’t have an option for GPU anywhere, including looking in the system section under user preferences.
Am I wrong and it is, in fact, not supported by the latest release?
Hi, Quadro 4000 is Cuda Capability 2.0 and is supported from Blender Cycles since the beginning of Cycles.
I have a 2.0 card too.
You need the latest driver.
What are your system specs, which Blender version and so forth?
You could try Octane demo, it is also a Cuda render engine, use demo files on same page:
The Quadro 4000 does work, but it is not that great of an improvement over CPU, on an 8 core or better machine. On OSX our tech department had to use the driver version one less than the release. Only the old drivers actually worked.