Parallels 15 (Pro) Desktop very slow on iMac Pro

Discussion in 'General Questions' started by ChristianS27, Aug 19, 2019.

  1. RichardT18

    RichardT18 Bit poster

    Just to add my experiences thus far w/Parallels v15.1.4. I'm running it on an older 21.5" iMac (late 2013) w/a Quad-Core Intel Core i5 & 16 GB of memory. The only VM I'm running is Windows 10. I use Office 365 apps primarily under the Windows 10 VM, almost always Excel. After I resume Windows 10 after launching Parallels, it's typically around 5 -7 minutes before I can get a response after clicking the start button. From that point, I can launch Excel and use it, although there is some lag. This definitely seems to be an unacceptable performance decrease over v14.
  2. DamienB2

    DamienB2 Member

    I'm nearly at the end of my tether with Parallels. I've always had both Parallels and WMware Fusion but the reason I have always primarily used Parallels is that they have some nice integration features over VMware and I also think the UI is laid out and bit better. And the performance difference between the two until v15 was negligible. But ultimately performance is key.

    I'm now trying to use nested virtualization and having even worse performance on top of the extremely slow performance at start up. To the point where the VM grinds to a halt trying to use things like Docker, WSL2, Windows Sandbox (it won't even start). It just unacceptable, and then testing it in WMware it all runs smoothly.

    My subscription is with Parallels is nearly due for renewal and I'm seriously thinking of just binning it and migrating all my VM's to VMware. If I have to pick, I pick performance over features any day.
  3. JohnE11

    JohnE11 Bit poster

    June 16 2020

    I just upgraded so Catalina (10.15.5) from Mojave. I am running Parallels 15.1.4. All of a sudden, both Windows 10 VM and Mojave 10.14.6 VM (so I can use 32 bit software) are DREADFULLY SLOW. Both were fine / fast under Mojave 10.14.6. We need a FIX form Parallels.
  4. RogerR4

    RogerR4 Bit poster

    I'm running MacOS Catalina 10.15.5 on a 2018 Mac mini (i7, 6 core, 16GB, 1 TB SSD), with Parallels 15 (version 15.1.4) and Windows 10 Pro (version 1909).Windows 10 has the default 2 Processors, but I upped the memory to 8 GB. It took 62 seconds for Firefox (already opened) to connect to, and over two minutes to a Quicken 2019 took over three minutes to open, but worked well once open. It also took almost a minute to open Windows Settings. Speedtest on the Mac side was 115 Mbps/11 Mbps; on the Windows side it was 4.25 Mbps/2.5 Mbps. It was all working well when I first upgraded Parallels from 14 to 15, then it slowed to a crawl when I updated 15. Help!
  5. JohnF34

    JohnF34 Bit poster

    I can confirm that I am running PD v15.1.4 on a MBP 13' 16GB 3.3Ghz i7. Catalina 10.15.5.

    I can confirm that this runs terribly slow!!!
  6. PaulM43

    PaulM43 Bit poster

    Wow, and here I thought this was just how slow Parallels is. I'm running a Catalina VM on a Catalina host OS (it's a long story) and the VM is dog slow. Scrolling is miserable, the key modifiers don't work right (e.g. I can cmd-tab fine, but can't cmd-shift-tab), and overall is barely usable. I only have to use it intermittently so it's not a huge deal, but I've been using it more recently and it's painful.

    I've submitted my technical data here: 343374583
  7. StuartW4

    StuartW4 Bit poster

    I had this exact same issue, but think I found the fix.
    I just bought a 2019 MacBook Pro 16, with 32gb of RAM, and intel i9, so should be more than powerful enough for running a virtual instance of windows using Parallels.
    I installed Parallels 15, and created a windows 10 installation.
    It ran INCREDIBLY slow, to the point where it was completely unusable.
    However, I played around with some settings, and think I have fixed it.
    Firstly, when creating the virtual machine, I selected the option to configure it from Development. This seemed to set all the settings to quite high (CPU was using 8 out of 8 cores).
    I reduced the core number down to 4, and set the memory at 16GB (16384MB).
    Finally, under the CPU advanced settings, I switched Hypervisor from Parallels to Apple *
    * THIS STAGE SEEMED TO BE WHAT FIXED IT FOR ME. The VM now runs fast and smoothly.
    WATERPROOF and Maria@Parallels like this.

    WATERPROOF Bit poster

    Config Imac Pro - Catalina - parallels 15 - both windows 10 & also windows 8.1 (I know...)
    Parallels ran very slow when launching huge memory consuming app (solidworks + keyshot) much more slowly than my oldest iMac 27 !!!
    I try to switch settings to APPLE HYPERVISOR (instead of Parallels hypervisor) as suggested by StuartW4 , restart the VM and it runs fast again !!!
    Thanks !!!!!
    StuartW4 likes this.
  9. StuartW4

    StuartW4 Bit poster

    I am so glad it worked for you also.
  10. NathanB8

    NathanB8 Bit poster

    StuartW4, this change also fixed my issues with Visual Studio 2019 and Parallels. I have the maxed out i9 iMac with 64GB of RAM and 2TB SSD. Yet with the Parallels hypervisor VS2019 was VERY slow. Do you know why the Apple Hypervisor is so much better? Do I lose anything from the Parallels hypervisor?
  11. StuartW4

    StuartW4 Bit poster

    I'm not sure of all the pros/cons, but the Apple Hypervisor certainly does sem to run faster.
    I have noticed the apple one has a slower startup/shutdown time of the VM, but I can live with that.
  12. MirkoD1

    MirkoD1 Bit poster


    I own a MacPRO6,1 (12-core Xeon, 2 x D700 and 64 GB RAM, macOS Catalina 10.15.6). I'm running Parallels Desktop 15.1.4 and I installed Solidworks 2019.
    It's EXTREMELY slow. Even with just one part, not to speak about assembly with 10 parts. I find it strange that such a (still) powerful machine is not able to manage Solidworks.
    Does anyone have a solution to that?
    Thanks in advance!

    ANTONIOF6 Bit poster

    Hello everyone.

    I have the same issue here. Upgraded to Parallels 15 on MacMini i5 2.5 with 16 GB RAM + 1 TB SSD and the performance is barely usable.
    I opened a ticket, sent dozens of reports and still no solution.
    Video performance sucks with Win 8.1 Pro and Win 10 VMs under Mojave.
    Catalina is NOT an option due to the fact it doesn't run 32-bit apps.
    Parallels 13 runs smoothly.

    I'm considering a downgrade since Parallels just tells me to wait.
  14. Hello, the reported issue is now under investigation with the Parallels Engineering Team.
    Once we get any updates we will contact you here or by email.
    Thank you for understanding.
  15. AllanS1

    AllanS1 Junior Member

    Parallels 16, 16" MacBook Pro with 64gb ram an i9 8 core processor and the problem still persists. I've followed this thread for over a year now since I upgraded to parallels 15 and started to have lagging and freezing in my windows 10 VMs. I've suffered enough in my work now that I have no choice but to move to VMware.
    Sorry parallels but you haven't listened to your [very] loyal users (over 7 years for me) and have failed them miserably!
    Sam33 likes this.
  16. Sam33

    Sam33 Junior Member

    How many cores did you give the VM? And which hypervisor are your running?
  17. AllanS1

    AllanS1 Junior Member

    2 processors assigned, 16gb ram and parallels hypervisor. All applications running slow and glitchy.
    rodneyh2 and Sam33 like this.
  18. rodneyh2

    rodneyh2 Bit poster

    I'm in the same boat. My primary W10 machine won't even render text on P16. Completely unusable, and I've tried multiple 16.x versions. P15 works but has been extremely slow (sometimes >20s to respond to a simple click), and it just comes on at random times, which doesn't work for me. I've moved to Fusion 12. It's certainly not as easy to setup as Parallels (although there's plentiful help on the interwebs), but it's very responsive and every bit as fast as P15 for my needs (mostly SW development). I don't know whether these are Parallels issues or macOS issues (I have 11.1), but enough is enough. I too have been a long term user. I think Parallels peaked around v12-13, since then it just seems to be less and less stable. I wish Parallels well, but you all have some work to do.
    AntonioR2 likes this.
  19. AntonioR2

    AntonioR2 Bit poster

    I, like @AllanS1 have a "Parallels 16, 16" MacBook Pro with 64gb ram an i9" but with 12 cores ... and with over 7 seven years of loyally utilizing Parallels. Ran perfectly on my 2014 15" and a pre P15 version of Parallels. Now with an upgraded computer I cannot even run a single instance of Visual Studio (same configurations my previous setup) without the processor topping out at 100% and Windows freezing!! I've relied on Parallels for years developing multi-platform software and even promoting them to a multitude of colleagues, but I'm fed up. I've waited for a solution because of their track record but it has been multiple versions in which this intolerable lag continues to plague my environment!
    I've checked all over for solutions and/or configurations but nothing...

    I will be checking out Fusion 12 TODAY!
  20. LarryW6

    LarryW6 Bit poster

    Yes, sadly the software seems to be performing WORSE over time. I am running the latest 16.x version with fully updated MacOS and seeing the same issues as all the rest. Most text not rendering today in File dialogs and other windows. Checking out Fusion 12 as well :(

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