MachineClaw When you register for the Pixels3d demo download, you can also download the PDF manuals for Pixels. They have a (IMO) good explanation of what most shader nodes do. hence instead of running native code, we're running ported/translated code. hence unstable and slow. What would make FireFly not native code? Renderers in general do not make any platform dependant function calls at all, they're just plain C or C++ floating point calculations. The reason why the Poser 4 renderer is faster is because it's incredibly primitive compared to FireFly. Also, the default settings for FireFly even in Draft mode. You can make it faster by reducing the number of pixel samples and increasing the values for min shading rate and bucket size. E.g. try pixel samples 1, and 128 for min shading rate and bucket size. With such settings, it's even faster than the Poser 4 renderer on my computer.