If you already have 4x DGX Sparks, you might not missing out much waiting for the 512 GB M5 Ultra. Here's why: Memory capacity: both 512 GB unified. Peak memory bandwidth: 4x Sparks: ~1092 GB/s aggregate (TP=4) M5 Ultra: ~1,200 GB/s They're almost identical on what matters most for local LLMs - memory capacity and bandwidth. Where the DGX Sparks still pull ahead Prefill is generally stronger, concurrency scales more cleanly, and the entire CUDA ecosystem (vLLM, TensorRT-LLM, etc.) is simply more mature for multi-node inference right now. Video and image generation will also probably be noticeably faster on the sparks due to CUDA. CUDA is still king. The Mac is cleaner and more efficient as a single box. But if you already own the 4x DGX Sparks, you can continue sleeping well.