I'm running an Ubuntu 14.04 LTS (32 bit) VirtualBox guest with >10GB storage and 2GB RAM on a Win7 (64-bit) laptop supporting VT-X. Like many others upgrading to 14.04 LTS noted here, Ubuntu runs very slow. The pace was tolerable until now.
I've enabled 3D Acceleration and set the controller SATA setting to use Host I/O Cache. I've toggled 32 and 64 bit. I don't know what else could be causing the performance decline as I have other guest operating systems working fine on same box.
Any suggestions are welcomed.