Hi! I`m rendering animation with smoke and fire sims in scenes. Do I understand correctly the following idea - if I set tile size e.g. 512, then first frame, where my sims are not visible yet, will render e.g. in 20 seconds, and as my animation progress and sims are more visible and more in action, then with the same tile size of 512, my render time will become longer?
Hi Gatis,
Performance depends on a lot of things and when it comes to tiling, CPU prefers smaller tiles (like 32) and GPU is faster with larger tiles.
Now, since Blender 3.0, Cycles has been completely re-written and sort of expects you to render on a GPU. Cycles in 3.0+ is faster on a GPU than in 2.93 or before on a GPU, but rendering on a CPU is a lot(!) slower than before 3.0.
The default in 3.0+ is using a tile size of 2048 and that is pretty good for a modern GPU.
When rendering an animation, you can render 1 still frame and try to optimize the render time for that frame, and then render the animation (best to first render as images). Most likely, the render time for the animation will then also be optimal.
There are no general 'best settings' for rendering unfortunately, it depends on your hardware, your scene and more.
So, to your question: yes, your render time per frame will increase as the simulations get more complicated over time.
Remember if the animation is too much for your computer, there are services like Sheepit that can be a life saver:
It's probably time to re-record this course to reflect current standards for rendering with Cycles (and Eevee). There's a potentially helpful segment in the SESSIONS Minimalism course that might help answer your question. Please see this lesson starting around 13:40