I am getting really poor performance while using Ubuntu 12.04 even though i have the latest drivers installed and can run fedora 16 without a hitch. The launcher takes 15 - 30 seconds to respond, switching between workspaces provides poor framerates, basic applications jitter a lot etc.

I am unable to discern the cause for this.

My config is:

Biostar T5XE motherboard
Intel Core i7 860
AMD Radeon HD 5770
4GB ram.