virtualbox.org

I'm running the "IE11 on Win7" pre-built VM from Microsoft's modern.ie site (first post, so can't link URLs) on my Mid 2011 13" MacBook Air (1.7Gz i5 with 4GB of RAM) running OS X 10.10.5, with VB 5.0.2. The only changes I made to the VM (from what MS provide) were:

• up the RAM to 2GB
• up the VRAM to 128MB
• Enable USB 2.0 and add 2 USB filters

Whenever the VM is running the Mac's CPU is pegged at 100% and the fan kicks in immediately even if the guest is doing absolutely nothing. If I give the guest 2 CPUs, the host CPU pegs at 200% (both cores fully used). Win7 guest performance is very good in some areas (booting up is very quick), but unusable in others (launching Chrome and getting to a point where I can type something in the address bar takes several minutes). I have previously (a year or so ago) run Win7 and Linux guests using VB on the same machine with no issues.

Before posting I searched here and the rest of the net for similar issues, but those that are mentioned all seem to be related to much earlier versions of VB.

I want to see if things would be better with VB 4.3.30, can I just downgrade, are the VMs backwards compatible?

Did you install the matching guest additions into the guest? The GAs from modern.ie tend to be older.

Yes, I installed the matching guest additions. Sorry, forgot to mention that.

no problem. I can tell you my Windows 7 guest (not from modern.ie) uses about 9.4% of the CPU at idle.

One thing that slows Windows 7 guests down is having automatically check for updates enabled. Try disabling it altogether.

loukingjr wrote:One thing that slows Windows 7 guests down is having automatically check for updates enabled. Try disabling it altogether.

Thanks. I'll try that and report back.

Incredibly, disabling automatic updates solved the problem . Now my Windows 7 guest uses around 10-12% CPU at idle. Thanks for the tip!

you're welcome. it's actually mpack's tip though.