Parallels Mac OS EL Capitan, Windows 10 very slow Bad performance issue

Everything worked perfectly on Yosemite. I was annoyed by the bug and tried and proved:
(1) the transfer speed between el capitan and external ssd is normal, indicate: it's not a pure failure of el capitan.
(2) try the trial version of VMWare Fusion (I try it to reveal the bug and offer more info for debug), I put the virtual machine on external ssd, everything is normal, indicate: there should be some bug with Parallel Desktop.
(3) I copy the virtual machine from external ssd to my host machine, everything is normal.
Clearly, it's a bug here, easy to be repeated again and again on all devices, it should be possible to be debugged !

 

I have the exact same problem with Parallels11 with Windows10 on a external Samsung T1 (it is faster than my inter SSD of MBP).
Over 100% CPU utilization and everything extremely slow.
Once I copy the .pvm file to the MBP internal, everything is fixed and fast.
THE PROBLEM is WITH PARALLELS & SAMSUNG T1 USB3 external drives!!
Please fix this guys.

 

We need this addressed. I'm experiencing the exact same thing as YangZ1. Everything worked perfectly on Yosemite.
(1) the transfer speed between El Capitan and external ssd is normal.
(2) I run the virtual machine on my hard drive, everything is normal.
(3) I put the virtual machine on external ssd, and Parallel Desktop works at a snails pace. And just barely.
(4) I copy the virtual machine from external ssd back to my hard drive, and everything is normal again.
Again, this was not a problem until El Capitan.

 

I'm having the same issue running Windows 7 with Parallels 11 on my iMac with everything running from the built-in HD. EXTREMELY slow after upgrading to El Capitan.
Curiously, my Macbook Air running Windows 7 and Parallels 11 has had no issues since upgrading to El Capitan and runs as speedily as ever.
Please fix this guys! Parallels is unusable on my iMac.

 

I have the exact same problem. Windows 7 was running perfectly on an external HDD with Version 10 on Yosemite. I upgraded to El Capitan and the VM is so slow it is unusable. I then upgraded to Parallels 11 hoping it would fix the issue but it still remains. THIS HAS TO BE FIXED ASAP!

 

I came to this thread because I am deciding if I want to upgrade to Parallels 11 Desktop right now. I am also trying to decide about Windows 10. Currently I am running Windows 8.1 on Parallels 10 (latest build) on a 2014 rMBP Pro. I use it in windowed or full screen mode, finding fewer problems in general by avoiding advanced Mac integration features. After upgrading to El Capitan I found no changes whatsoever in performance and wonder if I don't happen to be in a "sweet spot." Most of the issues seem to be with Windows 7 and/or Parallels 11 in this thread. Guess maybe I'll wait.

 

The problem is with both Parallels 10 & 11 and I believe it affects any virtual machine running from an external disk on El Capitan. I am using a SATA II 1.5 terabyte Seagate Barracuda in a USB 3.0 hard drive dock. It has worked flawlessly for me for over a year right up until I upgraded from Yosemite to El Capitan.

 

It looks like Parallel Desktop has no plan to fix this, this problem has been complained for a while, I am pushed to use the VMware Fusion trial for a while.

 

I'm having the same problem. I'm using Windows 10 on Parallels 11 and it was working perfectly under Yosemite. After I upgraded to El Capitan, the performance dropped SIGNIFICANTLY. Come on, guys. This is not the first time it happens.

 

Having the same issue. El Cap, Parallels 11, Windows 10 VM, External Samsung T1 SSD. The strange thing is that on my MBP, it runs at full speed, but on my iMac it's unusably slow. Other VMs (Windows Server 2012, Windows Server 2008, Windows 8.1) function fine on the same SSD.

Report #2196848, no help what so ever.

 

Isn't it working well why we bought the upgrade? Don't sell it to me before it is ready. I know it takes time, do a good job then release the update. Don't make me think everything is ready to go for the updates and have me deal with this horrible mess. Its ok to say it is not ready yet, 10.10 and parallels worked fine. The trends going on with the computer industry need to change. iD had it right, you'll get it when it is done, not when you want it.

 

Support guy wanted me to schedule a session where they could remote into my box to see what the problem was.

I told him to get bent, go to the store and buy a Samsung T1 SSD so they could figure out the problem on their end using their own time and not waste mine.

 

I have been suffering with the same problem.
I do however have a solution that worked for me:
Config>Hardware>CPU>Advanced>Enabled Nested virtualisation & Enable PMU virtualisation turned OFF
I think they are defaults when selecting a VM to do development. I dont need them. Performance is 1000% better.
Let me know if this helps anyone else. Parallels should obviously look into this.

 

Sounds good! Hope this solution helps the other users.

 

It doesn't work for me. Windows 8.1 is very slow after turn off these options.
It has certainly improved performance but still very very slow.

 

I'm also having the exact same issue and I'm not using an Samsung SSD. I'm using an external Toshiba SSD where I've migrated my bootcamp particion to as a parallels VM because I want to delete my bootcamp and start to use parallels. I'm a developer so I have Visual Studio, SQL Server and other developer tools ans as you can imagine its an absolute pain.

I had got Parallels 10 a few months ago but after I upgrated to El capitain I had to upgrade to Parallels 11. Not a good experience I must say. So I decided to go the extra mile and buy the Pro anual subscription. But these issues. This is making parallels unusable for most scenarios. Right now I'm installing SQL Server 2012 sp2 and I can't do anything else. I have the machine almost unusable. The only thing that is working is Edge, where I'm posting this.

Some extra information that may be related, not sure, but the VM is unstable:
- I stated to install Sql server 2012 sp2 because sql server management studio stopped working. SP2 finished installing and it still crashes
- Control panel crashes also some times. Dont know why
- I had to reboot my VM machine twice before I could open an butlocker external usb drive mapped to the VM
- If I try to copy a file from the VM to an external USB drive it gets over 50% cpu usage
- On every reboot the dual screen does not work. I have to put the VM on window mode and then on full screen again for it to use both screens
- If I have thge mac on power its much much faster than when I have it on battery power. It does not make sense because its so much slow that its impossible to use

I'm starting to think that I've made a bad call moving from Bootcamp to parallels.

Hope you guys sort this out soon.

 

Not sure what I'm doing differently, but I do not see that option. When I open Parallels 11 and go to:
Configue>Hardware but I see CPU "& Memory" and no Advanced Option. Am I just going to the wrong place?

 

Unfortunately, it doesnot work. It's a shame that parallel desktop cannot fix such severe bug after the release.

 

I'm having the same issue as everyone else, plus, every five minutes, I get the message "Deleting Snapshot..." and then I can't use Parallels for 10-15 minutes until it reappears. I barely need to use Windows and could care less about taking "Snapshots"--under Yosemite, Parallels was very fast and it didn't even seem like I was working on a VM. Windows 10 is a vast improvement on my Windows machine, but in VM mode on Parallels the performance is TERRIBLE.

 

The same issue. After upgrading OSX to el Capitan Parallels Desktop, both 10 and 11, show unacceptably slow performance when run from an external drive.
I use Windows 7 guest OS, the drive is an SSD SanDisk Extreme 500 240GB (model SDSSDEXT-240G).
As for others, the problem does not occur when Parallels is run from the internal drive.