MacBook Air Fan goes non stop when running Parallels or VMware

So I have the MacBook Air 13" the last gen model 2011 or whatever it is. I have Lion on it which it came with, and I had bought Parallels to run Windows 7 which worked fine, but then switched to VMware. Both worked perfect, I'd have Windows running 24/7 and always forget it was even running at the same time as my Mac.

2 days ago I formatted my machine and reinstalled Lion as the hard drive was really full and I wanted a fresh install. I installed VMware with Windows 7 again, but I notice that any time VMware is running my fan is going full blast non stop. Even if I stop the virtual machine just having VMware running keeps the fan going until I quit. So I just installed my Parallels copy that I have and I noticed it does the exact same thing.

Before I never would even remember I had Windows running and sometimes would have it running for days and the fan never even would turn on or go crazy. I did a SMC reset and NVRAm and PRAM but it still does it. Just really confused why it would suddenly do that now when before like I said you'd never notice it. I have it set to use 1 processor core and 1GB of my 4GB ram. I'm at a loss here, any ideas what might cause this?

Open your Activity Monitor app the next time the fans start going full blast. Take a look at what's eating up the CPU and memory causing the heat, and thus the fans to ramp up.

That's the thing, I always do open it and there's nothing out of the ordinary. Like everything is using normal amounts of ram, 80mb here and there, CPU always 0% or maybe jumps to 2% and what not but nothing crazy, that's what I don't get. Before I'd always check and yeah you'd see Shockwave Flash running at 60% CPU or something crazy and force stop it but when it does it now there's nothing out of the ordinary.

That is unusual. If the fans are going full blast when you run VMWare or Parallels, there has to be something else going on at the same time. The fan is only going to ramp up if the heat sensor tells it that something (the CPU) is getting hot. I've run VMWare many times and it has never done what you describe.

I would try completely uninstalling VMWare and Parallels and reinstall only one of them. You don't need to have them both on your MBA at the same time. Removing them will not remove the virtual machines but backup everything anyway just in case.

I'd definitely try what chscag suggested, but also did you change any of the settings for the vm's for parallels or vmware like using 3d acceleration? If you did (or even if the software is taking advantage of the GPU regardless of advanced VM settings) that could be generating heat without showing additional activity (the HD3000 GPU on the i5 and i7 would not show use on the activity monitor as the monitor only shows CPU usage, and although they are on the same chip, the HD3000 use isn't reflected in the actual CPU usage).

I have not problems w/ Parallels on MBA2011 or 2012

I only use it to run Win7, IE9, Office and a bit of Evernote and MindManager. So no games. But I have had not issues and no extraordinary fan noise when running Parallels (7) on my MBA mid-2011 (4GB memory and 256GB SSD) and my MBA 2012 (8GB memory and 512GB SSD). I don't run games or video on Parallels. And I somewhat limit the CPU and memory to about half of the machine. I also set the Parallels options to favor a faster Mac and longer battery life.

Same Problem

Hey, I have exactly the same problem. I have a MB Air 11" from 2011 and about 2-3 months ago, the fan started kicking into overdrive every time I start Windows 7 under Parallels 7. This happens without any programs being opened in Windows 7 (OK, I have Norton Internet Security running in the background, but I had that before too when there was no issue with the fan).

Any other ideas here what the problem could be?

prl_vm_app ???

OK, when I look into my Mac Activity Monitor, I can see that when I start Parallels that a process called "prl_vm_app" uses up more then 100% of CPU and constantly increases RAM usage (a minute ago it was at 400MB, now it is at 800MB, without any programs being opened in Windows 7).

And when I press the blue Info button in the Mac Activity Monitor and look under Opened Files and Ports, I can see that the "prl_vm_app" process opens all my files on my NAS drive, one after the other.

Could it be that we have some nice spyware on our machines that not even Norton identifies?

What is interesting is that after 2 hours or so, the fan stops spinning. I guess that the prl_vm_app process then has gathered all the info about what's on my NAS.

Also, I remember that this fan spinning stuff actually started once I installed Kaspersky on my Mac as suggested by Parallels. But I have long de-installed Kaspersky...

Very strange...

Also, I remember that this fan spinning stuff actually started once I installed Kaspersky on my Mac as suggested by Parallels. But I have long de-installed Kaspersky...

Click to expand...

I suspect that you haven't removed all the junk that Kaspersky installs, maybe a kext that was left behind and possibly running a process in the background. We have received reports before of the same thing happening as you've documented.

chscag said:

I suspect that you haven't removed all the junk that Kaspersky installs, maybe a kext that was left behind and possibly running a process in the background. We have received reports before of the same thing happening as you've documented.

Click to expand...

That could very well be the case...

I have also found the following thread on the Parallels forum and mentioned my problem there, too: prl_vm_app @ 99.9% CPU on Mac OS X 10.7 - Page 3 - Parallels Forums

Some of them seem to have solved the issue by stopping any indexing done by Windows. But this hasn't worked for me.

Maybe I'll have to do a clean re-install to solve this problem...

MacBook Air fan noise while Windows runs

FWIW, my hardware is pretty much identical to edokids' but I run Parallels and my fan started spinning incessantly and obnoxiously only AFTER upgrading to Mavericks and Parallels 8. (Like his, though, the fan shuts down as soon as I exit Parallels.)

It was maddening.

Finally, I went in to the "configure" utility for Parallels and did two things: reduced the video memory from 256mb to 128mb and disabled 3D Acceleration.

Did that about an hour ago and the **** fan hasn't come on ... so far.

I don't game on the Windows side ... only running Outlook and our company's inventory control software on that OS, so I don't think I'll miss the downgraded video settings.

Maybe something to put out there in case it can help others.