Ride with the Mighty Photons
Suppose you have finished a project and want to get the final output with Octane Render. When you press the magic "Render" icon, what do you think is going on in the background? How does Octane work? We want to talk about it briefly, for those who still have a sense of curiosity.
When you start Render, first, all the data on the scene is collected and sent to the Octane Core Engine. The CPU and the Core Plugin are playing a major role here. Yes, CPU. It's still responsible for some things in Octane. A CPU with a good performance shortens the scene export time and compilation process (especially "compilation"). After the scene data in Octane Core Engine is processed, the compilation process starts (that's why we see "preparing" in the bottom left corner). Once this is done, the GPU goes in and the "image sampling" starts. According to the Render settings and GPU specs, we see FINAL output after the sampling is finished. The following diagram illustrates the process.
"Why do I care?" or "How does it affect me?". You can ask such questions. We will have to make a few statements.
First of all, if you are seeing that scary and endless "preparing" process in heavy scenes for a long time, then you are in trouble. So obviously your scene definitely needs an optimization.
Let us give you a general idea: if there is any "calculation" in the background before the render, this will adversely affect both the scene export and the compilation process. In addition, any object that does not make a difference in appearance, but contains unnecessarily much polygons will extend the scene export and compilation. For example, if you need 4 segments to manipulate the cube object, it does not make much sense to increase it. In short, all 3D renderers loves optimized scenes, real polygons and absolute data (baked data) during rendering. If you have a calculation process happening in your scene at any time (for example Cinema 4D's Delay Effector) you should reduce it to a minimum or Bake it. This is a golden rule. And unfortunately Cinema 4D has a bad reputation in this matter. Especially if you are using some of the Mograph tools, particles, dynamics, cloth etc., the effect is very obvious.
Before you do the final render, do not leave anything unnecessary things in your scene. A very sloppy and messed up scenes are always a problem, it does not matter if you have the best software in the world. Optimization is inevitable. Even in the simplest scene, make always optimization.
Now suppose you optimize your scene and see the effect on Octane. First of all, scene export speed will be increased (CPU and Plugin will be responsible for this process) and the compilation time will be shortened. Here is the CPU performance comes into play. The difference between an old-fashioned CPU and the new one will be reflected in the scene export and compilation time (not the render time, please do not confuse it).
The relationship between GPU, Image sampling and Final render depends entirely on the performance of your graphics card. The more powerful and the more GPUs you have, the shorter the image sampling takes, so you get a quick render.
Finally, we would like to mention that the number of PCI lanes in the CPU does not make a difference in GPU renderers. You can read very useful information about this topic from the link below.