>Starting with 4 virtual cores and 8 GB vRAM, where the VM ran perfectly briskly with around 5 GB of memory used, I stepped down to 3 cores and 6 GB, to discover that memory usage fell to 3.9 GB and everything worked well. With just 2 cores and 4 GB of memory only 3.1 GB of that was used, and the VM continued to handle those lightweight tasks normally.

Good reminder that there's a certain amount of memory tied up with each core (probably mainly page cache and concurrency handling etc).

> Starting with 4 virtual cores and 8 GB vRAM, where the VM ran perfectly briskly with around 5 GB of memory used

But... if you start applications inside your VM it will want the full 8 Gb you've allocated not the 5 Gb it uses at startup?

• stingraycharles

  today at 10:52 AM

  I don’t assume that macOS virtualization is advanced enough to support memory ballooning, or is that not what you’re referring to?

  • pyth0

    today at 11:04 AM

    I don't assume anything either, but a single Google search is enough to dispel that [1]

    [1] https://developer.apple.com/documentation/virtualization/vzv...

  • sgt

    today at 11:15 AM

    macOS is generally pretty amazing at efficient memory usage and VM handling. So even a 8GB machine can run pretty impressive workloads without having the user think the machine is underpowered.

  • nottorp

    today at 11:02 AM

    What will that help with if the host and guest combined need > physical ram?

I'm wondering if the Xcode simulator (without Xcode running) performs as well, my 2020 Intel MacBook Air has been incapable of running Safari in iOS smoothly for nearly all its life.