virtualbox.org

I'm running Windows 7 guest on Mac OS X 10.10.3 host, and whenever I go into seamless mode I get serious lag. Is there anything I can do to fix this?

Minimum information needed for assistance.

VirtualBox Version 4.3.28 Guest Additions Installed
Host: Mac OS X 10.10.3, 64 bit, 32 GB RAM
Guest: Windows 7 Ultimate 64 bit, 8 GB RAM

When I try to attach the log file, I'm getting an error. "The file is too big, maximum allowed size is 128 KiB."

compress the vbox.log

Right click the VM in the VirtualBoxGUI. Select "Show Log". Save "VBox.log" to a file. Compress that file and attach it to a message here. Make sure the VM is fully shut down beforehand.

Gotcha Here you go!

Sorry VirtualBox wasn't shut down on the first log, here's one after shutdown. My apologies.

the first thing I would do is reduce the number of cores for the guest to 2.

Thanks! Your advice seems to have worked!