Multi-GPU Render Engines for Cinema 4D (2026): Redshift, Octane, V-Ray GPU and Arnold GPU
Four common Cinema 4D engines can render on several GPUs. What changes between them:
- All four scale: Redshift, Octane, V-Ray GPU and Arnold GPU can render one frame across several NVIDIA GPUs.
- VRAM is per GPU: Adding GPUs adds speed, not memory: the scene must fit on each card.
- Licensing differs: Redshift GPU comes with current Cinema 4D subscriptions; Octane's GPU count depends on the OTOY plan; V-Ray and Arnold are licensed separately.
- Corona is CPU: Corona renders on the CPU, so multi-GPU hardware does not speed it up.
- On iRender: 2x, 4x or 8x RTX 4090 / 5090 servers with Cinema 4D, Redshift and Octane pre-installed; you add V-Ray or Arnold with your own license.
If you have more than one GPU, or plan to rent a multi-GPU machine, the render engine decides how much of that hardware you actually use. This guide compares how Redshift, Octane, V-Ray GPU and Arnold GPU handle several GPUs in Cinema 4D, from each vendor’s documentation. For a general engine comparison see the best render engine for Cinema 4D.
Checked against the Cinema 4D and Redshift, Octane, V-Ray and Arnold documentation, November 2026.
1. Which Cinema 4D engines render on multiple GPUs?
How each engine uses several GPUs
From each vendor's documentation. VRAM is per GPU in every case below.
| Engine | GPU hardware | Multi-GPU | Device selection |
|---|---|---|---|
| Redshift | NVIDIA (Win/Linux), Metal (Mac) | Yes; VRAM not combined (Maxon support) | Preferences › Renderer › Redshift › Compute Devices |
| Octane | NVIDIA (Win/Linux), Metal (Mac) | Yes; GPU count depends on the OTOY plan | Octane device settings |
| V-Ray GPU | NVIDIA CUDA / RTX | Yes; Chaos cites near-linear scaling | V-Ray GPU device list |
| Arnold GPU | NVIDIA, Maxwell or later | Yes; Autodesk: multiple GPUs improve performance | CUDA_VISIBLE_DEVICES |
| Corona | CPU renderer | Not a GPU engine | — |
2. How does each engine scale?
- Redshift: renders across all GPUs ticked under Compute Devices. See Redshift multi-GPU rendering and our Redshift benchmark.
- Octane: uses every enabled GPU; the number allowed depends on your OTOY plan (OTOY).
- V-Ray GPU: Chaos describes near-linear scaling with no limit on the number of rendering devices (Chaos); V-Ray for Cinema 4D offers GPU, CPU and hybrid rendering (Chaos).
- Arnold GPU: Autodesk states multiple GPUs improve performance (Autodesk), and the OptiX 8 rewrite brought better multi-GPU scaling (Autodesk).
3. Do multiple GPUs add up their VRAM?
No. Each GPU holds its own copy of the scene, so a 4x RTX 5090 machine renders scenes that fit in 32 GB, faster. When a scene is too big, use the engine’s out-of-core option; see Redshift out-of-core.
A note on sources about VRAM: Maxon's support article states that Redshift does not combine the VRAM when using multiple GPUs. Maxon's 3D rendering product page also lists "multi-GPU memory pooling" and says Redshift shares out-of-core memory across multiple cards. This article follows the support article: plan for every GPU holding the scene in its own VRAM. Check Maxon's latest documentation for your Redshift version.
4. How to enable multiple GPUs (step by step)
Settings checklist (follow line by line):
Redshift Edit › Preferences › Renderer › Redshift › Compute Devices .. tick every GPU Octane Octane device settings ......................................... enable every GPU V-Ray GPU Render engine .................................................. V-Ray GPU GPU device list ................................................ select every GPU Arnold GPU Render device .................................................. GPU Limit GPUs (optional) .......................................... CUDA_VISIBLE_DEVICES=0,1,2,3 Check ............................................................ all GPUs loaded in nvidia-smi
Step 1: Enable every GPU in the engine
Each engine has its own device list; tick all the GPUs you want to render with.
Step 2: Keep one GPU free if you need the viewport
On a workstation you also use for the interface, leaving one GPU unticked can keep Cinema 4D responsive during rendering.
Step 3: Check the scene fits on one GPU
Watch memory per GPU during a test frame; it must stay below each card’s VRAM.
Step 4: Compare render times
Render the same frame with 1, 2 and 4 GPUs to see how your scene scales.
Quick check: nvidia-smi shows load on every GPU during the test frame and no GPU runs out of memory.
Sources: Maxon, Maxon env variables, OTOY command line, Autodesk Arnold GPU
Selecting a subset of GPUs per job lets one machine render several frames at once; Maxon suggests this for better scaling.
5. Multi-GPU on a farm: SaaS or IaaS?
A SaaS render farm splits frames across its own nodes and handles licensing for supported engines. An IaaS render farm such as iRender rents you a whole 2x, 4x or 8x GPU machine, so every engine above uses all GPUs on one frame and you pick the settings. See SaaS vs IaaS render farm.
Multi-GPU rendering on iRender servers.
On iRender you rent a whole server with 2x, 4x or 8x RTX 5090 or RTX 4090 GPUs, with Cinema 4D and Redshift pre-installed; Prime members get activated Cinema 4D and Redshift licenses. Real render times are in our Redshift benchmark, and plans are on the Cinema 4D Redshift render farm page.
6. Multi-GPU render engines FAQ
Which Cinema 4D render engines support multiple GPUs?
Redshift, Octane, V-Ray GPU and Arnold GPU all support rendering on several NVIDIA GPUs. Corona is a CPU renderer.
Do multiple GPUs combine VRAM in Cinema 4D?
No. Maxon support states Redshift does not combine VRAM across GPUs, and the same per-GPU rule applies to other GPU engines: the scene must fit on each card.
How many GPUs can Octane use?
It depends on the OTOY plan; Octane Studio+ has no GPU limit. Check OTOY’s current plans.
How do I choose which GPUs Arnold uses?
Autodesk documents the CUDA_VISIBLE_DEVICES environment variable to limit which GPUs Arnold can see.
Is 8 GPUs always faster than 4?
More GPUs usually shorten render time for heavy frames, but scaling depends on the engine and scene. Test your own scene; for some tools 4 GPUs is the sweet spot.
Can I use V-Ray or Arnold on iRender?
Yes. You install V-Ray or Arnold yourself with your own license; Cinema 4D, Redshift and Octane are pre-installed.
