macOS guest on iMac Pro host, how to optimized the performance.

[mnahum]

Host : iMac Pro 2017 3.2Ghz 8 Core Xeon / 32 Gb of RAM running last OS (no matter when you read it will be the last OS)

Guest: macOS last OS (no matter when you read it will be the last OS)

I need a Guest who is really have good performance, I played with the number of CPU ( from 2 to 😎 and the memory ( from 2 to 😎 but no matter what I do, simple operation like opening the launcher are slow.

Any idea. / suggestion how to optimized?

[ColoradoMarmot]

The general rule of thumb is no more than N-1 virtual cores per guest (where N is the number of physical cores - not virtual/hyperthreaded) in the host, with a minimum of 2 for OSX guests.  OSX needs a minimum of 4GB of ram to run well (on both the host/guest, so balance it out).

Keep in mind that there is no 3d acceleration for OSX guests, so they will always run slower, and have UI glitches.

Last, if you use a Fusion drive, using a single virtual disk file (rather that split into 2GB chunks) can improve performance, as the OS will continually move the 2GB chunks from the SSD to the spinning disk.

[wila]

Hi,

In addition,  do not keep snapshots any longer than you need them.

That also means don't use "Auto protect" as first it doesn't protect you and second it also doesn't help for performance to always have several snapshots open.

Note that if you are not using a Fusion drive then I do recommend the split disk scheme. The single virtual disk file only helps for performance on a Fusion disk, on all other disk types use the "split into multiple files" option.

Minor nitpick. It hasn't been "2GB split disks" since Fusion 7, that limit has been upped to 4GB.

Also note that there's a size limit per slice depending on the virtual disk size.

Capacity                        Disk slice size

================================

<=128GB                      4GB (increased from 2GB)

>128GB && <2TB          Capacity / 32 (so maximum of 32 extents)

>=2TB                           2TB

Other side notes:

If you assign RAM to your virtual graphics adapter then that RAM is taken away from your host RAM (not the graphics adapter)

Standard network shares are faster than the Host Guest shared folder feature. Disabling HG shared folders is a troubleshooting step with performance issues.

If you use an antivirus product then make sure that it excludes your VM bundle as it will slow things down.

If you want to exclude your VMs from ending up in an APFS snapshot then you can store the VM in a HFS sparse image or HFS partition instead.

--

Wil

edit: reworded for clarification

[ColoradoMarmot]

Good points...and that tells you how long it's been since i actually looked.

One thing - I think that if the sparseimage or sparsebundle file is on an APFS drive then it'll still be snapshotted (the image file, not the VM).  For non-boot APFS drives it's possible to disable the snapshot feature as well.

[mnahum]

Thanks for the details ... I didn't know for the RAM.

I just don't understand why my LaunchPad is so slow ... it's the same in all the VM.

I will double check my AV ...