For the last 38 days, I have been measuring free and used space in my Mac’s boot container and its backup storage. Here’s what has happened, and how upgrading to macOS 27 changed it.
VM
In Tahoe and later, using Macs with Secure Enclaves, copying the login keychain between them won’t work. But migration should be successful, and can also be used to create new VMs, such as Golden Gate.
If you installed the first Xcode beta in macOS 26.5.1, it probably stopped you building any more VMs. Here’s what happened, and how to recover normal virtualisation, even creating Golden Gate beta VMs again.
Golden Gate is bringing more than AI. Here are some of the improvements already detailed, some cautions to be aware of, notes on running GG in a VM, Intel support info, and an app update.
When you need to check what’s in a potential phishing email, run a locked-down virtual machine for safety, as explained here.
Video and audio don’t appear to sync correctly when played back in a macOS VM on an Apple silicon host. Have you noticed the same or similar problems?
Latest Geekbench performance figures for macOS VMs, and testing of how few cores and how little memory is really needed: could you run a macOS VM usefully on a MacBook Neo?
Virtualising macOS, Linux and Windows on Intel Macs has been relatively straightforward, and device support left to the developer. That won’t work for Apple silicon Macs. This explains what happens, its strengths and limitations as a result.
In Ventura, VM disk performance was poor, with write speeds of 0.7 GB/s. How fast is it now in macOS 26.4, and how does using FileVault affect it? Plus a note on problems with BSIs in VMs.
Doesn’t macOS wear out internal SSDs quickly because of all the data it writes to them? Will my Mac’s SSD wear out prematurely? How can I tell?
