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

This is awful. I just updated to El Capitan on my MACbook pro and Windows 10 is useable. It took 2 minutes to load task manager. I tried some of the settings that was suggested in earlier threads but still no luck. I haven't tried the windows refresh yet but I did send in report 85706808. I was considering restoring a time machine backup to Yosemite but I really don't want to do that.

Luckily my MAC at work is still on Yosemite. I loaded Windows 10 on it a couple of days ago and I've had no issues. I was using a Windows 8.1 VM for over a year and it worked perfectly.
 
Just wanted to chime in because I had the exact same issue. Windows 7 was unusably slow on Samsung T1 Portable SSD connected to my Mac running El Capitan. I switched to VMWare and that fixed the problem.
 
Following these instructions:
http://kb.parallels.com/112091
Totally did the trick for me. I was at a point where I just could not use W10 on Parallels because of the "runtimebroker" process eating up CPU like crazy.

Update:
I take that back. Runtimebroker kicked in again after I restarted the VM, making W10 and by extension my MBP litterally impossible to use. I have stopped using Parallels because of that.
 
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Looks like I have found the issue I was having. El Capitan must treat USB drives differently to Yosemite. I had rebuilt my Mac and the Win 10 VM but performance was still poor. I have been running the VM on a Corsair GTX USB drive, on Yosemite it was perfect but on El Capitan it pauses ever few seconds or so. I copied the VM back to the internal drive and it is back to working without the pauses. Would be nice to know if I can fix the external drive issue, but for now it is OK.
 
I was able to fix this problem by reformatting my external SSD. It was formatted "ExFat." But when I reformatted to "Mac OS Extended (Journaled)" my performance improved significantly.
 
My external drive was also formatted as ExFAT, reformatted as Mac OS Extended (Journaled) performance was back to normal, as it is an SSD it is really quick now. Thanks for that tip. Should be a warning on Parallels site about not using ExFAT disks to hold your VMs.
 
I had the same problem with a brand new iMac retina with Fusion Disk. It was terrible slow, when I started Windows VM. I tried re-installing Windows, re-installing Paralells and more, but nothing helped. Finally I read here something about PMU virtualization or something like that. I started looking for it and found the Optimization tab under Options and de-activated Enable Adaptive Hypervisor and Free space: Real time virtual disc optimization. I tried starting the VM again and it was a huge difference. Then I read a bit about it and clicked for Enable Adaptive Hypervisor again and it was still much faster than before. So, for me, the Real time virtual disc optimization was the problem.
 
I am using a MacBook Pro (Early 2011, OS X 10.11.3) with Parallels Desktop (Version 11.1.2). My virtual machine has a Windows 10 Pro operating system (EFI boot, installed on my internal Samsung 840 EVO SSD).

Until yesterday, I had the same start problems, like the most of you described. - I saw the Windows flag and had to wait a few minutes until the boot process has been continued.
I tried it with the changes from Bagchi, unfortunatelly it changed nothing for me.

Therefore I checked the configuration again - just for fun. I noticed, that the "sharing for Bluetooth devices" and also the "USB 3.0 support" were not enabled (Hardware -> USB & Bluetooth). I enabled both and was surprised that the Windows boot process has been reduced to a few seconds.

I do not know why this is so, but perhaps it will help someone else.
 
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My external drive was also formatted as ExFAT, reformatted as Mac OS Extended (Journaled) performance was back to normal, as it is an SSD it is really quick now. Thanks for that tip. Should be a warning on Parallels site about not using ExFAT disks to hold your VMs.

Yup, reformatting the drive to Mac OS Extended file system seemed to do the trick. Thanks!
 
Performance issues for my Mac/VM as well. Migrated from a SanDisk 128GB USB to a new SSD Extreme 500 240GB, which shipped ExFAT pre-formatted. Thought of giving ExFat a chance, but it ends right now. Re-formatting the SSD to Mac OS Ext and BANG, it works!
 
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Performance issues for my Mac/VM as well. Migrated from a SanDisk 128GB USB to a new SSD Extreme 500 240GB, which shipped ExFAT pre-formatted. Thought of giving ExFat a chance, but it ends right now. Re-formatting the SSD to Mac OS Ext and BANG, it works!
Great! Feel free to reach out anytime. We are here to help! Thanks!
 
My own experience of running Parallels 11 virtual machines for W7 and W10 on El Capitan is an ongoing nightmare. One hoped that one would gain the best of both worlds, but instead it is has given me the worst of both worlds, and that far outweighs the benefits. The whole problem originates with OSX trying to be an improvement on Windows7 but instead it's ended up just being different and the user has to cope with those differences on a second-to-second basis. Please -- somebody write a single operating system without all the conflicts. Surely that's not too much to ask? Maybe with just a teensy 1 billion of the US military budget could be spent on this project and do far more for the world.
 
I too am experiencing speed issues which only got worse when applying all the fixes in the articles linked to by PaulChris@parallels (5 minute boot time is now 10). All, that is, except for a total clean re-install of Windows which I am loathe to do. Parallels has been great for years. Am disappointed and don't understand why no real fix exists.
 
I have the same problem El Capitan 10.11.5 on MBPr 15", running Parallels 11.2.0.
Works on internal drive, but Windows 8 VM is unusable on my Thunderbolt external drive.
Note the extreme latency on response time: this value can goes up to 47000 ms...

slow_windows.tiff
 
I was able to fix this problem by reformatting my external SSD. It was formatted "ExFat." But when I reformatted to "Mac OS Extended (Journaled)" my performance improved significantly.

I had the same problem with Windows 10 being super slow running off my Samsung T1 SSD in Parallels 11 after updating to El Capitan. Reforming my external SSD from ExFat to Mac OS Extended totally addressed the performance issues and my VM is back to normal. Thanks for this tip!!!
 
@PaulChris@Parallels Has this been added as the official fix to Parallels 10, 11, and 12 documentation? This solution worked for me as well. Seems like there should be a big, fat warning when running a VM from an external drive formatted as ExFAT that performance may be degraded.
 
I am having the same super slow problems. I've got a brand new iMac that I optimized specifically to run Parallels and Revit (for 3D drafting). Parallels was working well on my MacBook Pro, but it's awful on the iMac. Would that ExFat fit work for me? Everyone is mentioning external drives, so it may not apply to me. Where would I go to reform my SSD?
 
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