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Guide to Performance Tuning (Adding Memory and CPU cores)

The default macOS VM configuration ( assumes some sane defaults, however this may not reflect the actual topology or peformance capabilities of the underlaying machine.

Here's some tunable parameters to get the most of out QEMU:


The following line controls memory allocation. The default is 2GB of RAM.

Increase this as needed (limited to the real amount of memory in your machine).

    -m 2G \


The default configuration enables 4 threads, divided into CPUs with 2 cores each.

    -smp 4,cores=2 \

The following example describes all possible topology flags:

    -smp cores=4,threads=4,sockets=1 \