Blender supports both CPU and GPU rendering, and each has strengths depending on the scene, hardware, and rendering goals.
Here’s a breakdown based on benchmark behavior and characteristics, using some real-world hardware examples (e.g., AMD EPYC and RTX 4090).
Key Differences in Rendering Behavior
|Feature| GPU Rendering (Cycles) | CPU Rendering (Cycles)
|Speed| Typically 5–15× faster for most scenes | Slower, especially on single-core tasks
|Parallelism| Massive parallel cores (thousands) | High core count helps, but not as efficient
|Memory Limited to GPU VRAM (e.g. 24–96 GB) | Access to system RAM e.g.60–512GB
Access|
|Scene
Compatibility| Some nodes/modifiers unsupported | Full compatibility
|Startup Time| Fast for repeated frames, slower Slower per frame but more consistent
initial startup
|Viewport
Performance| Excellent (real-time feedback) | Slower preview in most cases|
Benchmarks (Based on Actual Hardware Tests)
Blender BMW Scene (Cycles, Blender 3.6+)
Hardware Setup Render Time (single frame)
RTX 4090 (x1) ~25 seconds
RTX 3090 (x2) ~30–35 seconds (combined)
RTX 3060 (x4) ~45–50 seconds
AMD EPYC 7702 (128 vCPU) ~1 min 20 sec – 1 min 40 sec
Intel Xeon E5-2660v2 (dual) ~3–4 minutes
Note: GPU times vary slightly based on tile size (optimal: 256×256) and VRAM availability.
When to Choose Each
Use GPU Rendering when:
- Your scene fits in available VRAM (e.g. <24 GB per card)
- You want faster renders with real-time preview
- You’re rendering many frames (animation rendering)
Use CPU Rendering when:
- The scene exceeds GPU memory (e.g. large displacements, volumetrics, complex geometry)
- You need compatibility with all Blender features
- You’re running simulations alongside renders (fluid, smoke, particles)
Or Use Both (Hybrid Mode):
- Blender lets you combine CPU + GPU in Cycles to squeeze extra power
(Preferences > System > Cycles Render Devices)
Real-World Notes
-
EPYC CPUs are excellent for stability and handling memory-intensive jobs.
*Great for large-scale baking, procedural geometry, and long simulations. -
RTX 4090 setups shine in render speed, especially with OptiX denoising and complex shaders.
*Very fast on large tile rendering, but VRAM limits still apply. -
RTX 3060 x4 setups offer a cost-effective alternative with parallel tasking, though each card has less VRAM (12 GB), so scene optimization is important.
What Are You Using?
Would love to hear what other Blender users are rendering with - especially if you’ve noticed tipping points where GPU stops being ideal. Hybrid setups, headless rendering, or large memory tests - all welcome.