If you are interested in learning more about machine learning, Bayes networks, and Tensorflow, you do not necessarily need to buy any hardware at the moment. You can start by learning the basics of machine learning theory and programming on your existing computer. There are plenty of free resources available online, such as online courses, tutorials, and forums, that can help you get started.
Regarding hardware, it depends on your specific needs and budget. Navi 41 is not yet released, and it is not clear how it will perform for machine learning tasks. However, if you are on a budget, you can consider purchasing a consumer-level GPU, such as the NVIDIA GeForce RTX series or the AMD Radeon RX series. These GPUs have good support for machine learning libraries, including Tensorflow, and can be used with Linux environments.
Tensorflow libraries can run on non-CUDA dedicated runtimes, such as ROCm, OpenCL, and Vulkan. ROCm is a platform for running HPC and AI workloads on AMD GPUs and CPUs. It supports various AMD GPUs, including Radeon Instinct, Radeon VII, and Radeon RX 5700 series, and it is compatible with Linux environments. However, compatibility with Intel Arc 770 is not yet clear, as it is a new architecture that has not yet been released.
As for starting with machine learning hardware, a dedicated GPU is recommended for training models faster. However, you can start with a CPU-only setup and move to a GPU when you need more performance. Additionally, cloud computing platforms, such as Amazon Web Services, Google Cloud Platform, or if you are looking for economical options then Ace Cloud GPU offer virtual machines with pre-installed machine learning libraries and GPUs, allowing you to experiment without investing in hardware upfront.