I have a CentOS guest running on VirtualBox with GNOME 3, which is using Windows 7 as a host. This guest is configured to use all 4 of my CPUs, 2GB of RAM (which is plenty), and 128MB of VRAM. The guest also has 3 monitors enabled. Guest additionas are installed and working.
The desktop performance unfortunately is very slow. I do not mean that the CPU performance is slow, it's just things like moving winodws, redrawing windows, resizing, scrolling, etc. There's an amount of lag that is tolerable, but it would be really useful if I can eliminate it.
I do not get this issue with Windows guests. So that means there probably is something misconfigured in the Linux guest. And the problem seems to be noticeably worse the more monitors I add to the guest. It feels as if I have absolutely no desktop acceleration while having the desktop composited at the same time.
Is there anything I can do to improve desktop performance of the Linux guest? Or is this a problem inherent to GNOME3 running under VirtualBox?
When I open top, and look at what is consuming CPU time, I notice that gnome-shell's CPU usage spikes up whenever I do these window operations I mentioned above. So there's something probably misconfigured in GNOME3 but I can't tell what it is.
Note: I'm only talking about desktop graphics performance. RAM/swap is not the problem here, and it's not the CPU either.