Lagging on iMac 5k retina, advice needed?

[WelshMatt983]

I have 2 iMacs next to each other, one is a 2011 and the other is a 2014 5k retina.

I run some software for work and it the same software has always lagged on the retina iMac (27") but works perfectly fine on the 2011 iMac (21.5", non retina). I tried everything years ago trying to get the software running smoothly on the 27" iMac with no joy unless I made the screen resolution really small.

I am looking to upgrade now and get a new Mac Mini and buy an external screen.

I was just wondering if anyone had any idea why it only lags on the large 5k retina screen, could it be something to do with it being a large 5k screen with only 60hz refresh rate? Do you think it would be ok on a 32" screen with higher refresh rate and from a more powerful mac mini?

Thanks in advance for any replies!

[granada29]

Would you please post a zipped zession log showing the 'lagging'.

1. Start your VM. Do not start from a 'saved' image
2. Do something that shows the 'lagging'
3. Shut the VM down

4. Right-click your VM's name in VirtualBox Manager
5. Select 'Show in Finder'
6. Open the Logs folder shown in the Finder window
7. Right-click VBox.log and select 'Compress'

Add a new post to this topic and use the 'Attachments' tab to add the compressed log to the post.

[WelshMatt983]

Ok thank you, I have now attached the file to this message. I tried it again just in case updated VirtualBox had changed something but still lags and not really useable for what I need it for. It also seems to make my host run slow, opening things and sometime get spinning wheel.

Like I mentioned in earlier post running the same software on an older iMac 2011 (non retina) it works perfectly and doesn't impact host much either.

[granada29]

A few things to tweak

1. Memory - you only have 4.9GB available but have allocated 7.7GB to your VM. Either free up memory on the host (i.e. shut down some other programs) or reduce your VM memory allocation to 4GB or less.

2. CPUs - You only need 2 (at most 3) CPUs allocated to your VM. The VM will (possibly) be starving the host of CPU resources.

3. You are running VirtualBox 7.0.6. The most recent version is VirtualBox 7.0.10. That said, the hardware and macOS version you are using might run better with VirtualBox 6.1.46. No promises, but it is something I would try.