XPU for Cycles
I’d like to propose adding XPU rendering support to Cycles, similar to what SideFX’s
Karma XPU
offers in Houdini or XPU Renderman (Pixar).
The idea is to enable simultaneous CPU + GPU rendering in a single unified kernel, rather than the current “choose CPU or GPU” workflow.
EDIT : i'm talking about a real XPU Rendering ! Not the classical hyrbid system like some peoples say "Blender already support XPU" but Nop, it's juste an hybrid system !
Why This Matters
Modern productions often involve huge environments, heavy volumetrics, and film-grade assets.
Today, if a scene no longer fits comfortably in GPU memory, artists must fall back to CPU rendering and lose the GPU’s speed advantage.
An XPU approach would:
- Leverage all hardware at once --> CPU cores and GPU compute working together, automatically balancing the load.
- Handle out-of-core memory more gracefully --> CPU RAM could pick up overflow without stopping the GPU.
- Scale better for massive scenes --> architectural visualization, VFX shots, or dense procedural setups would render faster and more reliably.
- Simplify the workflow --> no more last-minute device switches or maintaining separate render farms.
Practical Impact
Studios across Europe and worldwide frequently deal with gigantic datasets.
A native XPU engine would keep Cycles competitive with other DCCs while reducing hardware costs and render times.
Suggested User Experience
A new option “Cycles XPU” device option that intelligently distributes work across CPU and GPU,
with automatic fallback when GPU memory is exceeded, keeping the familiar Cycles interface intact.
Thanks for considering that like an avancement for cycles dues to modernes technology and better support for massive environnement in Blender and Render Engine !!
7 Comments
Cycles already can render with GPU and CPU simultaneously.
Just select both CPU and GPU devices in settings and render with Device "GPU"
Also I believe that since Cycles X (and maybe even before), Cycles is already able to switch to RAM and even disk storage even when rendering on GPU only so to be able to keep rendering when out of VRAM and avoid "out of memory" errors, though at the cost of significant performance loss.
Cycles doesn't support XPU rendering, it's not a real XPU system i'm inviting you to consider to read the documentation. Like that is a base classic hybrid system but not XPU ! And in facts inb the option you can't enable both (GPU & CPU) for rendering ! You can only in settings !
That is for XPU rendering, cycles doens't support it ! Is the features wanted btw
Don't write insulting "do Your own research" comments.
Tell me and others whats difference instead of wasting people time. I've already looked up Karma's documentation before and i dont see any meaningful differences.
My bad, but just to be clear, the current design is not an XPU system.
The current setup makes the CPU render a tile while the GPU waits for the CPU to finish before it can process another tile.
This “hybrid” approach creates a significant bottleneck.
In a true XPU system, the CPU and GPU can work on the same image simultaneously, so this bottleneck doesn’t exist and heavy scenes render much faster.
That’s how Cycles worked until Blender 2.93. Since Blender 3.0's Cycles X update of December 2021, the rendering system was rewritten.
Tl;dr:
Sources:
That's why this proposal is confusing, it's premised on bottlenecks that have been removed almost four years ago and tapes on it a tech label as solution.