GPU Rendering Overview

Last modified: 10 March 2025

OctaneRender® is a "GPU rendering engine," meaning it uses GPU cards for the rendering process. GPUs, or "graphics processing units" are specialized computing hardware cards that you add to your computer in a variety of ways (plug in slots, specialized cable interfaces, and so on.) GPUs are used in so many areas of computer science and entertainment today, with prices and capabilities ranging from game play to bitcoin mining to advanced AI and simulations. Octane will run on many different cards, and it is a good idea to know what your hardware needs are to use Octane efficiently and reliably.

As a "third party" rendering engine, OctaneRender will interface with your preferred DCC application (LightWave in the case of this document) via the host application's plugin system and SDK. When you install Octane, you install it into the plugin directory as specified by your Lightwave 3D version (in this case LightWave 2024) and hardware configuration (Macintosh or PC). OctaneRender for LightWave 3D lives inside of the application environment, much like people live in a house. As Octane is likely to be one of many plugins that you have installed, there may be times where conflicts arise, and those situations are covered elsewhere.

GPU cards are blindingly fast, often a thousand times faster than the GPU on your computer's motherboard. To get that speed, GPUs operate under certain constraints: limited "on-board" RAM (VRAM), a quality, reliable power supply, and so on. These constraints may also affect you under certain conditions, as you create content to render with OctaneRender.

To render with OctaneRender from Lightwave 3D, you follow a typical workflow:

  • Create a scene

  • Add objects to your scene

  • Add materials, lights, and cameras to your scene (viewing the results in Live Viewer)

  • Set your output parameters and render your scene

The LightWave 3D plug-in is the bridge between LightWave3d and the Octane Standalone application. You need both the Standalone and the LightWave plugin to render to OctaneRender from LightWave. Alternatively, you can use the LightWave plugin to create an orbx or animated orbx file to render directly in Octane Standalone.

So much happens before you get to the point of sending over a file to render — regardless of whether you render with in LightWave 3D or with Standalone — your VRAM will be consumed in a similar way.

VRAM Usage

This is one of the most important things to know, and to keep an eye on. Your memory consumption will affect how much you can render at one time. If you exceed the amount of available VRAM, you won't be able to proceed, and may even experience a crash. Therefore, understanding how to maximize your VRAM is something you need to know how to do. Fortunately, it is not a difficult task, but it does require a little attention to detail.

VRAM is consumed by a combination of polygons (your objects), VDB volumes, Octane volumes, materials, textures, shaders, lights, and cameras. Each GPU card has a specific amount of VRAM available (consult with the manufacturer's specifications for your card(s)). VRAM Issues

Once you start running into your VRAM headroom barrier, your computer may start to act strangely. LightWave or Octane may become slow to unresponsive. In some cases, you may experience a crash. There are several different factors which can contribute to this, outside of software problems. Resource Competition

There are many different factors regarding instability and GPUs. Like any add-on product, your GPU card(s) require drivers to operate. These drivers are loaded when you first start up your computer, and they reside in your computer's RAM. These drivers are like little bots that help your computer to draw images to your screen, make calculations, and so on. These drivers, as well as the operating system in general, tend to take up quite a bit of VRAM on their own, even before you start up LightWave 3D or Octane.

So, while you may have a card with 11GB of VRAM, you may only have 8-9 GB to actually use in your scene. Further, if other applications are running (such as when you use Adobe After Effects and LightWave 3D at the same time) more VRAM is allocated, which reduces the amount of available VRAM for OctaneRender. And, sometimes, the operating system allocates these resources in a manner that is incomplete, leading to system instability or performance lags.

In certain cases, OctaneRender may try to allocate VRAM that is no longer available, even though OctaneRender thinks it is. This can lead to crashes. Heat

If you have been heavily using your GPU for a while and pushing it hard, you will likely notice that your GPU temp will climb. GPUs will start to throttle performance as temps climb over 80 degrees centigrade. If your rig is running near 100(c) for any length of time, you risk damaging your GPU and VRAM, and will likely cause your computer to become unstable and crash prone. You do need to keep an eye on your temps. Many GPU cards are "air-cooled." These cards have huge fans and heat sinks on board. Air-cooled rigs are the easiest to build, but they are the least efficient, temperature-wise.

Hybrid GPU cards use a combination of self-contained liquid plumbed in and around the GPU chip, while letting the VRAM air cool. These cards still use large fans but do perform well under load. They also come with their own radiators and fans connected via tubing. The liquid runs through the tubing, carrying the heat away from the GPU to the radiator, where the fans and radiator fins dissipate enough heat from the hot chips.

The ultimate in GPU rigs are complete water-cooled systems, and can be rather elaborate -- in some cases, arguably works of art. These rigs are the kings of chill and allow your GPUs to run at maximum efficiency while under the heaviest loads. However, they are not for the faint of heart, and might be more trouble that they are worth for most people.

Power Supply Issues

GPUs are one of the most power-hungry components in your computer. If your rig has more than one GPU card, you may notice a variety of issues if your power supply is failing or a lower-quality part. PSU issues will cause instability, performance problems and even data corruption throughout your system, so a quality power supply that is rated to handle the power requirements of your system is essential.

Overclocking and Stability

If you are experiencing stability issues it could be due to the clock rate at which your GPU is currently set. Many GPU card vendors will ship cards that are overclocked, and overclocking contributes to instability. Fortunately, it is easy to temporarily disable overclocking by setting the Nvidia driver to Debug mode. This mode will force the GPU to operate at the specified clock rate.