Why are Apple Silicon VMs so different?

Original Article ↗ Hacker News Discussion ↗

Apple’s move to ARM-based Silicon has reshaped how virtualization works on Macs, enabling fast ARM macOS and Linux VMs via Apple’s Virtualization/Hypervisor frameworks and VirtIO, but making full x86-64 guests dependent on slower emulation. Developers report good results running x86-64 Linux binaries inside ARM VMs using Rosetta or Windows-on-ARM’s own translation layer (often via Docker, OrbStack, Parallels or UTM), yet fully virtualized x86 systems remain significantly slower and sometimes fragile. The thread also highlights platform limits and trade‑offs — such as the two‑macOS‑VM cap, lack of 32‑bit ARM virtualization, and Apple’s tight control over features like nested virtualization — alongside broader questions about iPad vs. Mac roles and the future of local vs. remote development setups.

State of x86‑64 on Apple Silicon

  • Fully virtualizing x86/x86‑64 OSes on Apple Silicon relies on emulation (e.g., pure QEMU) and is consistently described as “very slow.”
  • A common pattern: run an ARM64 OS (Linux or Windows) in a VM, then use that OS’s own x86 translation (Rosetta on Linux/macOS, Windows’ x86 emulation) for individual apps.
  • Some users report acceptable performance for CLI tools and light productivity; others hit instability (e.g., Elixir builds segfaulting) unless specific workarounds are applied.

Rosetta 2 in Linux VMs and Docker

  • Apple exposes Rosetta to ARM64 Linux guests via Virtualization.framework, enabling x86‑64 binaries inside an ARM VM with good performance.
  • Docker Desktop and tools like OrbStack and Lima/Colima use this to run amd64 containers on Apple Silicon; performance is often close to or sometimes better than high‑end Intel laptops.
  • Workarounds exist for QEMU JIT bugs (e.g., setting build flags for Erlang/Elixir) to avoid crashes.

VM Tools: Parallels, UTM, VMware, Others

  • Parallels + Windows 11 ARM is widely praised for general productivity and development; Windows’ built‑in x86 emulation is mostly “invisible and just works.”
  • Complaints about Parallels include ads/upsells, subscription licensing, poor Linux desktop UX (e.g., scrolling), and privacy‑policy concerns.
  • UTM (QEMU front‑end) is seen as usable but often slow for full x86 OS emulation; better when running ARM guests plus Rosetta.
  • OrbStack and Lima are highlighted as strong CLI‑oriented solutions for Linux on Apple Silicon, often replacing Docker Desktop.

VirtIO, Apple Virtualization, and macOS VM Limits

  • Discussion notes Apple’s transition to VirtIO and Virtualization.framework; VirtIO itself is not ARM‑ or Apple‑specific, but Apple started shipping host drivers with Apple Silicon.
  • macOS on Apple Silicon enforces a hard limit of two concurrent macOS VMs, both technically and contractually; Linux VMs are not subject to this limit.
  • Some report that macOS VMs cannot sign into Apple ID, making them less suitable for general desktop use.

Windows, Gaming, and Alternatives

  • Many Windows games run decently under Parallels + Windows ARM, but compatibility is hit‑or‑miss and kernel‑level anti‑cheat remains a major blocker.
  • For gaming, several commenters prefer Wine‑based solutions (CrossOver, Whisky, Game Porting Toolkit) or cloud gaming (e.g., GeForce Now) over full VMs.

Broader Themes and Complaints

  • Several argue that for heavy x86 workloads, a remote x86 server/workstation is more practical than local emulation.
  • There is frustration about missing nested virtualization on macOS guests despite hardware support, and about Apple’s licensing/strategic restrictions around VMs.