Dear Linux and Ubuntu pros, I have here a company notebook, and because the hdd is full encrypted I cannot install an extra partition for another system that I would like to use in my free time. And I really need another system, because this crap windows here with that much of antivirus, antispyware, anti-whatever on it is sooo slow and anoying.

What can I do? I could use an external usb hdd with another system. Because I would like to handle big files and so on, I dont want to use an sub stick. An usb 2.5hdd + ubuntu is what I think the best option.

Here are my question: Do I have to note something? Is Ubuntu running well on an external hdd? Do I have big performance problems (because of the usb hdd)? Should I buy a very fast hdd for much money or is it not that important? Any suggestions? Thank you :)