slow performance on new (2017) retina iMac

[davey jenk]

i am running virtual box with micro station (cad) quite well on this machine:

late 2013 27" retina iMac macOS sierra, 10.12.5
3.5Ghz i7 16GB Fusion drive
Nvidia gforce gtx 4GB

and i just installed it on this machine:

2017 27" retina iMac macOS sierra, 10.12.5
3.4 Ghz i5 16GB Fusion drive
Radeon pro 570 4GB

and it is SLOW and choppy. i've searched forums here and elsewhere for possible answers. any input or ideas welcomed.

thanks!

[socratis]

Your systems are really close; HiDPI, 10.12.5. I would like to see a log from both machines. To keep the noise at a minimum:

• Follow a "start the VM from cold-boot" / "observe error" / "shutdown the VM".
• With the VM shut down completely (not paused or saved), right-click on the VM in the VirtualBox Manager and select "Show Log".
• Save only the first "VBox.log", ZIP it and attach it to your response (see the "Upload attachment" tab below the reply form).

Do that as I said for BOTH systems.

[davey jenk]

i believe this is what you asked for. apologies if it's not and thanks for the help!

[davey jenk]

there is no error observed per se, it's just that the newer iMac is 3-4 times as slow booting, moving windows, really performing any function at all.

[mpack]

Well of course. You've assigned all 4 CPU cores to the VM. How is the host supposed to do anything well, like run VirtualBox?

[socratis]

Not only what mpack said (max. # vCPUs = 3), but you also got to fix the following:

00:00:01.025961 Host RAM: 16384MB (16.0GB) total, 9218MB (9.0GB) available
00:00:01.157728 RamSize  <integer> = 0x00000002ff400000 (12 872 318 976, 12 276 MB, 11 GB)
00:00:01.157988 VRamSize <integer> = 0x0000000008000000 (134 217 728, 128 MB)

12276 + 128 >> 9218.

You are assigning memory to your guest, that you do not have available. Either close some applications on the host, buy more RAM for the host, or reduce the amount of RAM assigned to the guest (I'd go for the last one). Your host is going to be swapping like crazy!

May I suggest a couple of applications, so that you know what's available on your system at any given time? What I do, is to have several monitor tools running at all times. Your preference may vary, but you can use either of them (I use all of them concurrently):

• MenuMeters (doesn't run on OSX > 10.10).
• X Resource Graph.
• Memory Monitor.
• Built-in Activity monitor.

[davey jenk]

first off, thanks for your replies. greatly appreciated.

i was told to use these settings per our local IT guy.

i believe this is an 8 core CPU so 4 is ok?

[davey jenk]

and he also told me to slide the ram over to the end of the green bar?

[davey jenk]

and again, i know you all know WAY MORE about this than i do, but the 2013 iMac is running just fine using the EXACT same settings. that's where i'm stumped

[davey jenk]

i restarted the iMac to purge ram, slid the bar down to 8GB for the VM, launched virtual box and still even dragging a window around the desktop is jerky and slow. this is an xrg screen shot with the VM running. it had 11GB free showing when i launched it.

[erdeslawe]

You believe wrongly! You have a CPU with 4 Physical Cores, but if you want to place more trust your local 'IT Guy' than the long time users of VirtualBox that you have asked for advice....

[davey jenk]

thanks for the reply. i'm on this board for that exact reason, because he pointed me to you experts here. so what do you recommend for the setting? is that graph that says i have 8 lying to me?

[mpack]

You don't need to trust us on the subject of how many cores an i5-7500 has, but I suggest that you do take Intel's word for it!
https://ark.intel.com/products/97123/In ... o-3_80-GHz

Yours is a straight up 4-core CPU, no hyperthreads even (not that VirtualBox has any use for the latter).

I suggest that you give no more than 2 cores to a VM. And why does it need so much RAM? 8GB strikes me as a decent, safe number.

[davey jenk]

thanks mpack, i sincerely appreciate the efforts and insights here.

please forgive my ignorance, but why does my slider in virtual box go up to 8 if there are only 4?

and why does it run so well on the 2013 iMac with the same settings?

these are the questions that leave me confused.

and for what it's worth, i decreased settings to 2 CPUs, and 8GB ram, and still slow and choppy.

getting really frustrated, but appreciative of all your help.

[mpack]

If the scenario has changed then please provide a new log.

why does my slider in virtual box go up to 8 if there are only 4?

I don't see how that observation can possibly correlate with the log file you previously provided. Even if VirtualBox misidentified the CPU, it would do it the same way both in the dialog and in the log.

But, lets not get bogged down in the cores vs threads discussion. Suffice to say that threads are irrelevant. We only care about cores, and you apparantly have 4, and you must not give them all to a VM.

Regarding the "CPU" hoggage - if all else fails you can use the tools provided by your OS. In Windows open the task manager / resource monitor, make sure the CPU and I/O columns are visible, and see which tasks are using it all. Note that an app may be using very little CPU if it is suspended while waiting on I/O. That's why it's important to look at the I/O hogs column too.