Windows 10 Speed on 4K Display

[Michael Pitt]

Hi All

I'm currently running PD12 - been a Parallels user for years and love it. I've recently purchased an external 4k monitor - everything works great until I boot up my Windows 10 VM in full screen. My Mac then crawls - if I move to a windowed view then performance is better although not brilliant. Using the built-in Retina display with no external monitor, performance is fine.

I'm assuming its the resolution that's an issue, but I'm not sure if the issue here is OSX or Parallels, as with no Parallels running the Mac is fine. If it is Parallels, should I be offering more System or Video memory to the VM to boost performance? Currently the VM has 1GB of video memory and 6GB of system memory.

Thanks,
Mike.

 

[DustinHullett]

1 GB of video memory should be more than enough. It may actually be whats slowing your OSX down to a crawl. Try lowering the video memory to 512MB and see if performance is better. It sounds like your host is starving for resources because the VM is using them up. Also are you using adaptive hypervisor? How many processor cores are configured for the VM and what Are your resolution settings? Scaled or best for retina?

 

[Michael Pitt]

Thanks - I'll give 512MB a try.

VM is configure for 4 processors, 6GB RAM and scaled display. My laptop is a 2013 MBP with 16GB RAM, 2.7GHz i7. Not using the 4K screen everything flies - its just when using the 4K monitor (with laptop lid closed, so not powering two high resolution screens).

If you have any other config advice that would be great.

 

[DustinHullett]

Also how are you connecting to your New 4K Display? Thunderbolt Mini display port or HDMI?

 

[Michael Pitt]

Thunderbolt Mini display port

 

[DustinHullett]

ok so the research i have done on this has revealed that this happens on some mac's without parallels running also. Your's though starts when parallels is booted up correct?
Have you reset your SMC and PRAM?
SMC RESET: https://support.apple.com/en-us/HT201295
PRAM RESET: https://support.apple.com/en-us/HT204063
Please monitor your cpu and energy usage with activity monitor with and without the issue, so with parallels booted and without parallels booted.
Also do you have the virtual machine and the mac configured to use your high performance GPU? It should switch by default when you plug in an external monitor but we want to be sure its switching.
In the same activity monitor energy window see if high performance gpu column has "yes" by parallels desktop or windows. Post anything that has a yes or a screenshot of these windows may be best.
I will do my best to help you get this issue resolved, Thanks

 

[Michael Pitt]

Hi

Thanks for the info - see attached screenshots of CPU/Energy with and without Parallels running.

I have GPU switching disabled so my Mac is always on the fast GPU/

Just going to reset my SMC and PRAM and then try with 512MB of video memory configured.

Thanks,
Mike.

 

[Michael Pitt]

It seems to be an issue with scaled 4K mode on the Mac. If I just leave the display at "Default for display") so its in full 4K res, then Parallels and the Mac are happy. If I move to scaled, it all becomes sluggish. I guess its the overhead of the Mac doing the scaling that just becomes more noticeable when Parallels is running?

 

[StuartE]

I had an issue with my MBP (Late 2013), running El Capitan, using a 4K display where it got stuck on integrated graphics.

You can confirm which graphics system is being used with About This Mac, it should say "NVidia" etc, if it says Intel, its using the built-in. This was even with graphics switching disabled.

Unplugging replugging a bunch of times seemed to fix it.

 

[ArvinF]

I have a MBP 16GB RAM, and a Windows 10 VM running at 8-core, 8GB RAM, and 2GB video memory. I am running an external display that is 43" 4K, 30Hz off HDMI 2.0. f I reduce my video memory to 512MB, the VM is unusable, screen updates are slowed down quite a lot. Can the experts who think 512MB of video memory is enough to support a 4K? Is that enough RAM to rapidly render that many pixel? From my tests, less than 2GB runs really badly.

 

[James Minnihan]

Check to see if the Parallels Service is showing "not responding" using Activity Monitor on your Mac side. I am seeing a 100% CPU spike inside Windows 10 Pro x64 VMs while running the Anniversary Update with the latest 10.12.4 macOS Sierra running the VM in a "scaled" window on a 28" 4K monitor. Also happens (although not as often) on a Windows 8.1 Pro x64 VM too. I am running on a 2015 MBP 15" 16GB RAM, 1 TB SSD, macOS Sierra 10.12.4, with both VM set to 2 CPU Cores, 8 GB RAM, 2048 MB Graphics, Advanced Hypervisor, and Better Performance.

 

[PaulChristopher@Parallels]

Check to see if the Parallels Service is showing "not responding" using Activity Monitor on your Mac side. I am seeing a 100% CPU spike inside Windows 10 Pro x64 VMs while running the Anniversary Update with the latest 10.12.4 macOS Sierra running the VM in a "scaled" window on a 28" 4K monitor. Also happens (although not as often) on a Windows 8.1 Pro x64 VM too. I am running on a 2015 MBP 15" 16GB RAM, 1 TB SSD, macOS Sierra 10.12.4, with both VM set to 2 CPU Cores, 8 GB RAM, 2048 MB Graphics, Advanced Hypervisor, and Better Performance.

Hi @James Minnihan, try switching between integrated and discrete video cards will resolve the issue.
To switch between the adapters, go to virtual machine configuration window -> Options -> Optimization - Power
* For integrated graphics (CPU) set 'Longer battery life'
* For discrete video card set 'Better performance'
You can also choose "No limit" for Resource usage.

 

[James Minnihan]

Here's what settings under Optimization I have already set when I see the pre-mentioned issue with the Parallels Service:

Performance: set to Faster virtual machine
Adaptive Hypervisor: checked
Tune Windows for speed: checked
Pause Windows when possible: unchecked
Power: set to Better Performance
Show battery in Windows: checked
Resource usage: set to No limit

I have a screen shot of macOS Sierra's 10.12.4's Activity Monitor, showing the hung Parallels Service:

I believe this started with the most recent version of Parallels 12.2.0 and macOS Sierra 10.12.4.