Stable Diffusion CUDA Out of Memory: How to Fix

Just want the answer? In most cases, you can fix this error by setting a lower image resolution or fewer images per generation. Or, use an app like NightCafe that runs Stable Diffusion online in the cloud so you don't need to deal with CUDA errors at all.

One of the best AI image generators currently available is Stable Diffusion online. It's a text-to-image technology that enables individuals to produce beautiful works of art in a matter of seconds. If you take the time to study a Stable Diffusion prompt guide, you can quickly make quality images with your computer or on the cloud, and learn what to do if you get a CUDA out-of-memory error message.

If Stable Diffusion is used locally on a computer rather than via a website or application programming interface, the machine will need to have certain capabilities to handle the program. Your graphics card is the most critical component when using Stable Diffusion because it operates almost entirely on a graphics processing unit (GPU)—and usually on a CUDA-based Nvidia GPU.

The Nvidia CUDA parallel computing platform is the foundation for thousands of GPU-accelerated applications. It is the platform of choice for developing and implementing novel deep learning and parallel computing algorithms due to CUDA's flexibility and programmability.

What Is CUDA?

NVIDIA developed the parallel computing platform and programming language called Compute Unified Device Architecture, or CUDA. Through GPU accelerators, CUDA has assisted developers in speeding up their apps with more than twenty million downloads.

In addition to speeding up applications for high-performance computing and research, CUDA has gained widespread use in consumer and commercial ecosystems, as well as open-source AI generators such as Stable Diffusion.

What Happens With a Memory Error in Stable Diffusion?

Running Stable Diffusion on your computer may occasionally cause memory problems and prevent the model from functioning correctly. This occurs when your GPU memory allocation is exhausted. It is important to note that running Stable Diffusion requires at least four gigabytes (GB) of video random access memory (VRAM). One recommendation is a 3xxx series NVIDIA GPU that starts with six GB of VRAM. Other components of your computer, such as your central processing unit (CPU), RAM, and storage devices, are less important.

To train an AI model on a GPU, you need to differentiate labels and predictions to be accurate. To produce reliable predictions, you need both the model and the input data to be allocated in CUDA memory. A memory error occurs when the project becomes too complex to be cached in the GPU's memory.

Each project has a specific quantity of data that needs to be uploaded, either to the VRAM (the GPU's memory when the CUDA or RTX GPU engine resides) or the RAM (when the CPU engine operates).

GPUs typically contain a significantly smaller amount of memory than a computer's RAM. A project may occasionally be too big and fail because it is fully uploaded to the VRAM. The geometry's intricacy, extent to which high-resolution textures are used, render settings, and other elements can all play a part.

How to Fix a Memory Error in Stable Diffusion

One of the easiest ways to fix a memory error issue is by simply restarting the computer. If this doesn’t work, another potential remedy is to reduce the resolution. Reduce your image to 256 x 256 resolution by making an input of -W 256 -H 256 in the command line.

You can also try increasing the memory that the CUDA device has access to. You do this by modifying your system's GPU settings. Changing the configuration file or using command-line options frequently resolves the issue.

Another option is to buy a new GPU. If you go this route, get a GPU with more memory to replace the existing GPU if VRAM is consistently causing runtime problems that other methods can’t solve. 

Divide the data into smaller batches. Processing smaller sets of data may be needed to avoid memory overload. This tactic reduces overall memory utilisation and the task can be completed without running out of memory.

You can also use a new framework. If you are using TensorFlow or PyTorch, you can switch to a more memory-efficient framework.

Finally, make your code more efficient to avoid memory issues. You can decrease the data size, use more effective methods, or try other speed enhancements.

In Conclusion

The best way to solve a memory problem in Stable Diffusion will depend on the specifics of your situation, including the volume of data being processed and the hardware and software employed.

You can further enhance your creations with Stable Diffusion samplers such as k_LMS, DDIM and k_euler_a. The incredible results happen without any pre- or post-processing.

Ready to take a deep dive into the Stable Diffusion universe? Sign up for a free account on NightCafe and let your creative ideas flow.