New SCALE tool enables CUDA applications to run on AMD GPUs

Spectral Compute has introduced SCALE, a new toolchain that allows CUDA programs to run directly on AMD GPUs without modifications to the code, reports Phoronix. SCALE can automatically compile existing CUDA code for AMD GPUs, which greatly simplifies transition of software originally developed for Nvidia hardware to other platforms without breaking any end user license agreements.  

Spectral’s SCALE is a toolkit, akin to Nvidia’s CUDA Toolkit, designed to generate binaries for non-Nvidia GPUs when compiling CUDA code. It strives for source compatibility with CUDA, including support for unique implementations like inline PTX as, and nvcc’s C++ implementation, though it can generate code compatible with AMD’s ROCm 6. One of SCALE’s significant advantages is its ability to act as a drop-in replacement for Nvidia’s own nvcc compiler. Therefore, unlike other projects that translate CUDA code to another language or use other manual steps, SCALE directly compiles CUDA sources for AMD GPUs.  

SCALE’s implementation leverages some open-source LLVM components to create a solution that is both efficient and user-friendly as the software package aims to offer a more seamless and integrated solution that ZLUDA, which is a translation layer that is prohibited to use. It even mimics the Nvidia CUDA Toolkit runtime, making it easier for developers to port their existing CUDA programs to AMD hardware. 

SCALE has undergone extensive testing with a variety of software, including Blender, Llama-cpp, XGboost, FAISS, GOMC, STDGPU, Hashcat, and Nvidia Thrust, and has proven that it works stably and correctly. Testing has been conducted on RDNA 2 and RDNA 3 GPUs, with basic testing on RDNA 1 and ongoing development for Vega support. The developers did not have access to AMD’s CDNA-based GPUs though.

The lack of support for CDNA-based processors is a disadvantage of SCALE because datacenter software designed using CUDA and for CUDA-compatible hardware dominates the rapidly growing AI space and many developers are interested in easily porting their programs to competing platforms, expanding their addressable market. 

Funding for SCALE has been provided by Spectral Compute’s consulting business since 2017, without financial backing from AMD. Although the program is not open source, there is a Free Edition License available and this one can be used for commercial applications.