Apple Silicon and macOS VMs: 11–16× Faster LLM Inference with llama.cpp Published on August 11, 2026 by Francesco Bonacci and Johnny Franks If you've been following Cua from the start, you may remember that it began with a Show HN launch for Lume, our macOS virtualization stack. A macOS guest running through Apple's Virtualization.framework uses a virtual GPU backed by the host's Apple GPU. In our stock Tahoe VM, that device reported a conservative Metal capability profile. Applications use those answers to select kernels and rendering paths, which left llama.cpp running much slower GPU code. We built a small, process-scoped compatibility layer that changes selected capability answers for one guest process, allowing llama.cpp to select newer Metal kernels. This is the first result from our broader effort to connect Lume's virtualization foundation to the local computer-use environments behind Cua Driver and the infrastructure behind Cua Cloud and Fleets .…