By all accounts I am a total Blender and CG noob. I started playing with blender a few months ago and discovered quickly that rendering took ages (~10 minutes).
Having a really old graphics card that appeared not to be compatible with Blender, rendering was going through the CPU. So, I bought the best card I could get that would be compatible with my old machine. (Gigabyte Geforce GTX 960 2GB).
I was expecting things to really improve, but rendering with the same settings and changing device to “GPU Compute” has only resulted in a x2 improvement (~5 minutes).
Am I doing something completely wrong? I don’t know what I don’t know. What is a good way to learn more about whatever it is I don’t know?
Many thanks! Cam
SUMMARY / terse version:
Blender noob, just bought a new graphics card, not sure it’s working optimally
There are some settings, that gpu-rendering will benefit when changed. One most used is the Tile size in Redering panel under Performance tab. Using cpu it is usually smaller, eg. 64x64, but with gpu you could use something like 256x256. There is no exact right number, because it is gpu and scene specific.
Blender foundation also has great scenes to test and compare. Try them out:
The first thing you should accept is that in offline CG, 10 minutes for a frame is on the short end. It’s not unusual for a production frame to take hours to render. It has “always” been like this, because even though computers get faster, rendering methods get more expensive as well. Cycles is a “brute force” path tracer, which is pretty much the most expensive way to render.
I was expecting things to really improve, but rendering with the same settings and changing device to “GPU Compute” has only resulted in a x2 improvement (~5 minutes).
Depending on your CPU, a 2x speedup for this sort of GPU (midrange) seems ordinary. In “real” scenes, the speedup between a decent quadcore CPU and a higher-end GPU is maybe about 5x, sometimes less. In any case, make sure to adjust your tile sizes to be larger on the GPU.
+1 with BeerBaron. Time required can also be influenced by what is being rendered and how it is constructed. A scene with a person in normal clothing may take a long time to render but could take less time if you add a hat (no hair to consider), face mask (fewer facial features), and/or chunky body armor (less clothing). Put all of that in a dimly lit corridor (as opposed to a reflectively-shiny clean-room look) and there will be more gains.